S02_CH15_ AXI_OLED 实验

在上一个例子中，主要是以软件功能为主，采用了软件模拟SPI时序进行控制OLED。这样做的好处是灵活，但是牺牲了效率。本章采用的方式是让SPI驱动由Verilog实现，字库也是保存到了PL部分的BRAM中。这种方式是减轻了CPU负担，提高了CPU效率。缺点是没有上一章的方法灵活。

15.1 自定义IP的封装

Step1：新建一个名为Miz_sys空的工程。

Step2：选择Tools Create and Package IP 创建IP

Step3:单击NEXT

Step4:由于我们需要挂在到总线上，因此创建一个带AXI总线的用户IP

Step5:设置IP的名字为SSD1306_OLED_ML版本号默认，并且记住IP的位置

Step6:设置总线形式为Lite总线，Lite总线是简化的AXI总线消耗的资源少，当然性能也是比完全版的AXI总线差一点，但是由于音频的速度并不高，因此采用Lite总线就够了，设置寄存器数量为17，因为后面我们需要用到17个寄存器。

Step7:选择Edit IP单击Finish完成

15.2 SSD1306_OLED_ML用户IP的修改

IP创建完成后，并不能立马使用，还需要做一些修改。

Step1:打开SSD1306_OLED_ML.v文件在以下位置修改：

Step2:用以下程序替代SSD1306_OLED_ML_v1_0_S00_AXI.v。

`timescale 1 ns / 1 ps

//////////////////////////////////////////////////////////////////////////////////

//

//

// Create Date:    06:13:25 08/18/2014

// Module Name:    SSD1306_OLED_v1_0_S00_AXI

// Project Name:  SSD1306_OLED

// Target Devices: Zynq

// Tool versions:  Vivado 14.2 (64-bits)

// Description: The core is a slave AXI peripheral with 17 software-accessed registers.

// registers 0-16 are used for data, register 17 is the control register

//

// Revision: 1.0 - SSD1306_OLED_v1_0_S00_AXI completed

// Revision 0.01 - File Created

//

//////////////////////////////////////////////////////////////////////////////////

module SSD1306_OLED_v1_0_S00_AXI #

(

// Width of S_AXI data bus

parameter integer C_S_AXI_DATA_WIDTH = 32,

// Width of S_AXI address bus

parameter integer C_S_AXI_ADDR_WIDTH = 7

)

(

// Interface with the SSD1306 starts here

//SPI Data In (MOSI)

output  SDIN,

//SPI Clock

output  SCLK,

//Data_Command Control

output  DC,

//Power Reset

output  RES,

//Battery Voltage Control - connected to field-effect transistors-active low

output  VBAT,

// Logic Voltage Control - connected to field-effect transistors-active low

output  VDD,

// Interface with the SSD1306 ends here

// Global Clock Signal

input wire  S_AXI_ACLK,

// Global Reset Signal. This Signal is Active LOW

input wire  S_AXI_ARESETN,

// Write address (issued by master, acceped by Slave)

input wire [C_S_AXI_ADDR_WIDTH-1 : 0] S_AXI_AWADDR,

// Write channel Protection type. This signal indicates the

// privilege and security level of the transaction, and whether

// the transaction is a data access or an instruction access.

input wire [2 : 0] S_AXI_AWPROT,

// Write address valid. This signal indicates that the master signaling

// valid write address and control information.

input wire  S_AXI_AWVALID,

// Write address ready. This signal indicates that the slave is ready

// to accept an address and associated control signals.

output wire  S_AXI_AWREADY,

// Write data (issued by master, acceped by Slave)

input wire [C_S_AXI_DATA_WIDTH-1 : 0] S_AXI_WDATA,

// Write strobes. This signal indicates which byte lanes hold

// valid data. There is one write strobe bit for each eight

// bits of the write data bus.    

input wire [(C_S_AXI_DATA_WIDTH/8)-1 : 0] S_AXI_WSTRB,

// Write valid. This signal indicates that valid write

// data and strobes are available.

input wire  S_AXI_WVALID,

// Write ready. This signal indicates that the slave

// can accept the write data.

output wire  S_AXI_WREADY,

// Write response. This signal indicates the status

// of the write transaction.

output wire [1 : 0] S_AXI_BRESP,

// Write response valid. This signal indicates that the channel

// is signaling a valid write response.

output wire  S_AXI_BVALID,

// Response ready. This signal indicates that the master

// can accept a write response.

input wire  S_AXI_BREADY,

// Read address (issued by master, acceped by Slave)

input wire [C_S_AXI_ADDR_WIDTH-1 : 0] S_AXI_ARADDR,

// Protection type. This signal indicates the privilege

// and security level of the transaction, and whether the

// transaction is a data access or an instruction access.

input wire [2 : 0] S_AXI_ARPROT,

// Read address valid. This signal indicates that the channel

// is signaling valid read address and control information.

input wire  S_AXI_ARVALID,

// Read address ready. This signal indicates that the slave is

// ready to accept an address and associated control signals.

output wire  S_AXI_ARREADY,

// Read data (issued by slave)

output wire [C_S_AXI_DATA_WIDTH-1 : 0] S_AXI_RDATA,

// Read response. This signal indicates the status of the

// read transfer.

output wire [1 : 0] S_AXI_RRESP,

// Read valid. This signal indicates that the channel is

// signaling the required read data.

output wire  S_AXI_RVALID,

// Read ready. This signal indicates that the master can

// accept the read data and response information.

input wire  S_AXI_RREADY

);

// AXI4LITE signals

reg [C_S_AXI_ADDR_WIDTH-1 : 0] axi_awaddr;

reg   axi_awready;

reg   axi_wready;

reg [1 : 0] axi_bresp;

reg   axi_bvalid;

reg [C_S_AXI_ADDR_WIDTH-1 : 0] axi_araddr;

reg   axi_arready;

reg [C_S_AXI_DATA_WIDTH-1 : 0] axi_rdata;

reg [1 : 0] axi_rresp;

reg   axi_rvalid;

// Example-specific design signals

// local parameter for addressing 32 bit / 64 bit C_S_AXI_DATA_WIDTH

// ADDR_LSB is used for addressing 32/64 bit registers/memories

// ADDR_LSB = 2 for 32 bits (n downto 2)

// ADDR_LSB = 3 for 64 bits (n downto 3)

localparam integer ADDR_LSB = (C_S_AXI_DATA_WIDTH/32) + 1;

localparam integer OPT_MEM_ADDR_BITS = 4;

//----------------------------------------------

//-- Signals for user logic register space example

//------------------------------------------------

//-- Number of Slave Registers 17

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg0;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg1;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg2;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg3;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg4;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg5;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg6;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg7;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg8;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg9;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg10;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg11;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg12;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg13;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg14;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg15;

reg [C_S_AXI_DATA_WIDTH-1:0] slv_reg16;

wire  slv_reg_rden;

wire  slv_reg_wren;

reg [C_S_AXI_DATA_WIDTH-1:0]  reg_data_out;

integer  byte_index;

// I/O Connections assignments

assign S_AXI_AWREADY = axi_awready;

assign S_AXI_WREADY = axi_wready;

assign S_AXI_BRESP = axi_bresp;

assign S_AXI_BVALID = axi_bvalid;

assign S_AXI_ARREADY = axi_arready;

assign S_AXI_RDATA = axi_rdata;

assign S_AXI_RRESP = axi_rresp;

assign S_AXI_RVALID = axi_rvalid;

// Implement axi_awready generation

// axi_awready is asserted for one S_AXI_ACLK clock cycle when both

// S_AXI_AWVALID and S_AXI_WVALID are asserted. axi_awready is

// de-asserted when reset is low.

// ===========================================================================

//   Parameters, Regsiters, and Wires

// ===========================================================================

//Current overall state of the state machine

reg [143:0] current_state;

//State to go to after the SPI transmission is finished

reg [111:0] after_state;

//State to go to after the set page sequence

reg [142:0] after_page_state;

//State to go to after sending the character sequence

reg [95:0] after_char_state;

//State to go to after the UpdateScreen is finished

reg [39:0] after_update_state;

//Variable that contains what the screen will be after the next UpdateScreen state

reg [7:0]        current_screen[0:3][0:15];

//Variable assigned to the SSD1306 interface

reg temp_dc = 1'b0;

reg temp_res = 1'b1;

reg temp_vbat = 1'b1;

reg temp_vdd = 1'b1;

assign DC = temp_dc;

assign RES = temp_res;

assign VBAT = temp_vbat;

assign VDD = temp_vdd;

//-------------- Variables used in the Delay Controller Block --------------

wire [11:0] temp_delay_ms; //amount of ms to delay

reg temp_delay_en = 1'b0;  //Enable signal for the delay block

wire temp_delay_fin;       //Finish signal for the delay block

assign temp_delay_ms = (after_state == "DispContrast1") ? 12'h074 : 12'h014;

//-------------- Variables used in the SPI controller block ----------------

reg temp_spi_en = 1'b0;     //Enable signal for the SPI block

reg [7:0] temp_spi_data = 8'h00; //Data to be sent out on SPI

wire temp_spi_fin; //Finish signal for the SPI block

//-------------- Variables used in the characters libtray  ----------------

reg [7:0] temp_char; //Contains ASCII value for character

reg [10:0] temp_addr; //Contains address to BYTE needed in memory

wire [7:0] temp_dout; //Contains byte outputted from memory

reg [1:0] temp_page; //Current page

reg [3:0] temp_index; //Current character on page

//-------------- Variables used in the reset and synchronization circuitry   ----------------

reg init_first_r = 1'b1;    // Initilaize only one time

reg clear_screen_i = 1'b1;  // Clear the screen on start up

reg ready = 1'b0;           // Ready flag

reg RST_internal =1'b1;

reg[11:0] count =12'h000;

wire RST_IN;

wire RST=1'b0; // dummy wire - can be connected as a port to provide external reset to the circuit

integer i = 0;

integer j = 0;

assign RST_IN = (RST || RST_internal);

//--------------  Core commands assignments start ----------------

wire Display_c;

wire Clear_c;

assign Display_c = slv_reg16[0];

assign Clear_c =slv_reg16[1];

//--------------  Core commands assignments end ----------------

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_awready <= 1'b0;

end

else

begin    

if (~axi_awready && S_AXI_AWVALID && S_AXI_WVALID)

begin

// slave is ready to accept write address when

// there is a valid write address and write data

// on the write address and data bus. This design

// expects no outstanding transactions.

axi_awready <= 1'b1;

end

else           

begin

axi_awready <= 1'b0;

end

end

end       

// Implement axi_awaddr latching

// This process is used to latch the address when both

// S_AXI_AWVALID and S_AXI_WVALID are valid.

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_awaddr <= 0;

end

else

begin    

if (~axi_awready && S_AXI_AWVALID && S_AXI_WVALID)

begin

// Write Address latching

axi_awaddr <= S_AXI_AWADDR;

end

end

end       

// Implement axi_wready generation

// axi_wready is asserted for one S_AXI_ACLK clock cycle when both

// S_AXI_AWVALID and S_AXI_WVALID are asserted. axi_wready is

// de-asserted when reset is low.

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_wready <= 1'b0;

end

else

begin    

if (~axi_wready && S_AXI_WVALID && S_AXI_AWVALID)

begin

// slave is ready to accept write data when

// there is a valid write address and write data

// on the write address and data bus. This design

// expects no outstanding transactions.

axi_wready <= 1'b1;

end

else

begin

axi_wready <= 1'b0;

end

end

end       

// Implement memory mapped register select and write logic generation

// The write data is accepted and written to memory mapped registers when

// axi_awready, S_AXI_WVALID, axi_wready and S_AXI_WVALID are asserted. Write strobes are used to

// select byte enables of slave registers while writing.

// These registers are cleared when reset (active low) is applied.

// Slave register write enable is asserted when valid address and data are available

// and the slave is ready to accept the write address and write data.

assign slv_reg_wren = axi_wready && S_AXI_WVALID && axi_awready && S_AXI_AWVALID;

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

slv_reg0 <= 0;

slv_reg1 <= 0;

slv_reg2 <= 0;

slv_reg3 <= 0;

slv_reg4 <= 0;

slv_reg5 <= 0;

slv_reg6 <= 0;

slv_reg7 <= 0;

slv_reg8 <= 0;

slv_reg9 <= 0;

slv_reg10 <= 0;

slv_reg11 <= 0;

slv_reg12 <= 0;

slv_reg13 <= 0;

slv_reg14 <= 0;

slv_reg15 <= 0;

slv_reg16 <= 0;

end

else begin

if (slv_reg_wren)

begin

case ( axi_awaddr[ADDR_LSB+OPT_MEM_ADDR_BITS:ADDR_LSB] )

5'h00:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 0

slv_reg0[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h01:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 1

slv_reg1[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h02:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 2

slv_reg2[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h03:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 3

slv_reg3[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h04:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 4

slv_reg4[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h05:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 5

slv_reg5[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h06:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 6

slv_reg6[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h07:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 7

slv_reg7[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h08:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 8

slv_reg8[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h09:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 9

slv_reg9[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0A:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 10

slv_reg10[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0B:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 11

slv_reg11[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0C:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 12

slv_reg12[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0D:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 13

slv_reg13[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0E:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 14

slv_reg14[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h0F:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 15

slv_reg15[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

5'h10:

for ( byte_index = 0; byte_index <= (C_S_AXI_DATA_WIDTH/8)-1; byte_index = byte_index+1 )

if ( S_AXI_WSTRB[byte_index] == 1 ) begin

// Respective byte enables are asserted as per write strobes

// Slave register 16

slv_reg16[(byte_index*8) +: 8] <= S_AXI_WDATA[(byte_index*8) +: 8];

end  

default : begin

slv_reg0 <= slv_reg0;

slv_reg1 <= slv_reg1;

slv_reg2 <= slv_reg2;

slv_reg3 <= slv_reg3;

slv_reg4 <= slv_reg4;

slv_reg5 <= slv_reg5;

slv_reg6 <= slv_reg6;

slv_reg7 <= slv_reg7;

slv_reg8 <= slv_reg8;

slv_reg9 <= slv_reg9;

slv_reg10 <= slv_reg10;

slv_reg11 <= slv_reg11;

slv_reg12 <= slv_reg12;

slv_reg13 <= slv_reg13;

slv_reg14 <= slv_reg14;

slv_reg15 <= slv_reg15;

slv_reg16 <= slv_reg16;

end

endcase

end

end

end    

// Implement write response logic generation

// The write response and response valid signals are asserted by the slave

// when axi_wready, S_AXI_WVALID, axi_wready and S_AXI_WVALID are asserted.  

// This marks the acceptance of address and indicates the status of

// write transaction.

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_bvalid  <= 0;

axi_bresp   <= 2'b0;

end

else

begin    

if (axi_awready && S_AXI_AWVALID && ~axi_bvalid && axi_wready && S_AXI_WVALID)

begin

// indicates a valid write response is available

axi_bvalid <= 1'b1;

axi_bresp  <= 2'b0; // 'OKAY' response

end                   // work error responses in future

else

begin

if (S_AXI_BREADY && axi_bvalid)

//check if bready is asserted while bvalid is high)

//(there is a possibility that bready is always asserted high)   

begin

axi_bvalid <= 1'b0;

end  

end

end

end   

// Implement axi_arready generation

// axi_arready is asserted for one S_AXI_ACLK clock cycle when

// S_AXI_ARVALID is asserted. axi_awready is

// de-asserted when reset (active low) is asserted.

// The read address is also latched when S_AXI_ARVALID is

// asserted. axi_araddr is reset to zero on reset assertion.

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_arready <= 1'b0;

axi_araddr  <= 32'b0;

end

else

begin    

if (~axi_arready && S_AXI_ARVALID)

begin

// indicates that the slave has acceped the valid read address

axi_arready <= 1'b1;

// Read address latching

axi_araddr  <= S_AXI_ARADDR;

end

else

begin

axi_arready <= 1'b0;

end

end

end       

// Implement axi_arvalid generation

// axi_rvalid is asserted for one S_AXI_ACLK clock cycle when both

// S_AXI_ARVALID and axi_arready are asserted. The slave registers

// data are available on the axi_rdata bus at this instance. The

// assertion of axi_rvalid marks the validity of read data on the

// bus and axi_rresp indicates the status of read transaction.axi_rvalid

// is deasserted on reset (active low). axi_rresp and axi_rdata are

// cleared to zero on reset (active low).  

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_rvalid <= 0;

axi_rresp  <= 0;

end

else

begin    

if (axi_arready && S_AXI_ARVALID && ~axi_rvalid)

begin

// Valid read data is available at the read data bus

axi_rvalid <= 1'b1;

axi_rresp  <= 2'b0; // 'OKAY' response

end   

else if (axi_rvalid && S_AXI_RREADY)

begin

// Read data is accepted by the master

axi_rvalid <= 1'b0;

end                

end

end    

// Implement memory mapped register select and read logic generation

// Slave register read enable is asserted when valid address is available

// and the slave is ready to accept the read address.

assign slv_reg_rden = axi_arready & S_AXI_ARVALID & ~axi_rvalid;

always @(*)

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

reg_data_out <= 0;

end

else

begin    

// Address decoding for reading registers

case ( axi_araddr[ADDR_LSB+OPT_MEM_ADDR_BITS:ADDR_LSB] )

5'h00   : reg_data_out <= slv_reg0;

5'h01   : reg_data_out <= slv_reg1;

5'h02   : reg_data_out <= slv_reg2;

5'h03   : reg_data_out <= slv_reg3;

5'h04   : reg_data_out <= slv_reg4;

5'h05   : reg_data_out <= slv_reg5;

5'h06   : reg_data_out <= slv_reg6;

5'h07   : reg_data_out <= slv_reg7;

5'h08   : reg_data_out <= slv_reg8;

5'h09   : reg_data_out <= slv_reg9;

5'h0A   : reg_data_out <= slv_reg10;

5'h0B   : reg_data_out <= slv_reg11;

5'h0C   : reg_data_out <= slv_reg12;

5'h0D   : reg_data_out <= slv_reg13;

5'h0E   : reg_data_out <= slv_reg14;

5'h0F   : reg_data_out <= slv_reg15;

5'h10   : reg_data_out <= slv_reg16;

default : reg_data_out <= 0;

endcase

end   

end

// Output register or memory read data

always @( posedge S_AXI_ACLK )

begin

if ( S_AXI_ARESETN == 1'b0 )

begin

axi_rdata  <= 0;

end

else

begin    

// When there is a valid read address (S_AXI_ARVALID) with

// acceptance of read address by the slave (axi_arready),

// output the read dada

if (slv_reg_rden)

begin

axi_rdata <= reg_data_out;     // register read data

end   

end

end    

// ===========================================================================

// Implementation

// ===========================================================================

SpiCtrl SPI_COMP(

.CLK(S_AXI_ACLK),

.RST(RST_IN),

.SPI_EN(temp_spi_en),

.SPI_DATA(temp_spi_data),

.SDO(SDIN),

.SCLK(SCLK),

.SPI_FIN(temp_spi_fin)

);

Delay DELAY_COMP(

.CLK(S_AXI_ACLK),

.RST(RST_IN),

.DELAY_MS(temp_delay_ms),

.DELAY_EN(temp_delay_en),

.DELAY_FIN(temp_delay_fin)

);

charLib CHAR_LIB_COMP(

.clka(S_AXI_ACLK),

.addra(temp_addr),

.douta(temp_dout)

);

// State Machine

always @(posedge S_AXI_ACLK) begin

if(RST_IN == 1'b1) begin

current_state <= "Idle";

temp_res <= 1'b0;

end

else begin

temp_res <= 1'b1;

case(current_state)

// Idle State

"Idle" : begin

if(init_first_r == 1'b1) begin

temp_dc <= 1'b0; // DC= 0 "Commands" , DC=1 "Data"

current_state <= "VddOn";

init_first_r <= 1'b0; // Don't go over the initialization more than once

end

else begin

current_state <="WaitRequest";

end

end

// Initialization Sequence

// This should be done only one time when Zedboard starts

"VddOn" : begin // turn the power on the logic of the display

temp_vdd <= 1'b0; // remember the power FET transistor for VDD is active low

current_state <= "Wait1";

end

// 3

"Wait1" : begin

after_state <= "DispOff";

current_state <= "Transition3";

end

// 4

"DispOff" : begin

temp_spi_data <= 8'hAE; // 0xAE= Set Display OFF

after_state <= "SetClockDiv1";

current_state <= "Transition1";

end

// 5

"SetClockDiv1" : begin  

temp_spi_data <= 8'hD5; //0xD5

after_state <= "SetClockDiv2";

current_state <= "Transition1";

end

// 6

"SetClockDiv2" : begin

temp_spi_data <= 8'h80; // 0x80

after_state <= "MultiPlex1";

current_state <= "Transition1";

end

// 7

"MultiPlex1" : begin  

temp_spi_data <= 8'hA8; //0xA8

after_state <= "MultiPlex2";

current_state <= "Transition1";

end

// 8

"MultiPlex2" : begin

temp_spi_data <= 8'h1F; // 0x1F

after_state <= "ChargePump1";

current_state <= "Transition1";

end

// 9

"ChargePump1" : begin  //  Access Charge Pump Setting

temp_spi_data <= 8'h8D; //0x8D

after_state <= "ChargePump2";

current_state <= "Transition1";

end

// 10

"ChargePump2" : begin //  Enable Charge Pump

temp_spi_data <= 8'h14; // 0x14

after_state <= "PreCharge1";

current_state <= "Transition1";

end

// 11

"PreCharge1" : begin // Access Pre-charge Period Setting

temp_spi_data <= 8'hD9; // 0xD9

after_state <= "PreCharge2";

current_state <= "Transition1";

end

// 12

"PreCharge2" : begin //Set the Pre-charge Period

temp_spi_data <= 8'hFF; // 0xF1

after_state <= "VCOMH1";

current_state <= "Transition1";

end

// 13

"VCOMH1" : begin //Set the Pre-charge Period

temp_spi_data <= 8'hDB; // 0xF1

after_state <= "VCOMH2";

current_state <= "Transition1";

end

// 14

"VCOMH2" : begin //Set the Pre-charge Period

temp_spi_data <= 8'h40; // 0xF1

after_state <= "DispContrast1";

current_state <= "Transition1";

end

// 15

"DispContrast1" : begin //Set Contrast Control for BANK0

temp_spi_data <= 8'h81; // 0x81

after_state <= "DispContrast2";

current_state <= "Transition1";

end

// 16

"DispContrast2" : begin

temp_spi_data <= 8'hF1; // 0x0F

after_state <= "InvertDisp1";

current_state <= "Transition1";

end

// 17

"InvertDisp1" : begin

temp_spi_data <= 8'hA0; // 0xA1

after_state <= "InvertDisp2";

current_state <= "Transition1";

end

// 18

"InvertDisp2" : begin

temp_spi_data <= 8'hC0; // 0xC0

after_state <= "ComConfig1";

current_state <= "Transition1";

end

// 19

"ComConfig1" : begin

temp_spi_data <= 8'hDA; // 0xDA

after_state <= "ComConfig2";

current_state <= "Transition1";

end

// 20

"ComConfig2" : begin

temp_spi_data <= 8'h02; // 0x02

after_state <= "VbatOn";

current_state <= "Transition1";

end

// 21

"VbatOn" : begin

temp_vbat <= 1'b0;

current_state <= "Wait3";

end

// 22

"Wait3" : begin

after_state <= "ResetOn";

current_state <= "Transition3";

end

// 23

"ResetOn" : begin

temp_res <= 1'b0;

current_state <= "Wait2";

end

// 24

"Wait2" : begin

after_state <= "ResetOff";

current_state <= "Transition3";

end

// 25

"ResetOff" : begin

temp_res <= 1'b1;

current_state <= "WaitRequest";

end

// ************ END Initialization sequence but without turnning the dispay on ************

// Main state

"WaitRequest" : begin

if(Display_c == 1'b1) begin

current_state <= "ClearDC";

after_page_state <= "ReadRegisters";

temp_page <= 2'b00;

end

else if ((Clear_c==1'b1) || (clear_screen_i == 1'b1)) begin

current_state <= "ClearDC";

after_page_state <= "ClearScreen";

temp_page <= 2'b00;

end

else begin

current_state<="WaitRequest"; // keep looping in the WaitRequest state untill you receive a command

if ((clear_screen_i == 1'b0) && (ready ==1'b0)) begin  // this part is only executed once, on start-up

temp_spi_data <= 8'hAF; // 0xAF // Dispaly ON

after_state <= "WaitRequest";

current_state <= "Transition1";

temp_dc<=1'b0;

ready <= 1'b1;

end

end

end

//Update Page states

//1. Sets DC to command mode

//2. Sends the SetPage Command

//3. Sends the Page to be set to

//4. Sets the start pixel to the left column

//5. Sets DC to data mode

"ClearDC" : begin

temp_dc <= 1'b0;

current_state <= "SetPage";

end

"SetPage" : begin

temp_spi_data <= 8'b00100010;

after_state <= "PageNum";

current_state <= "Transition1";

end

"PageNum" : begin

temp_spi_data <= {6'b000000,temp_page};

after_state <= "LeftColumn1";

current_state <= "Transition1";

end

"LeftColumn1" : begin

temp_spi_data <= 8'b00000000;

after_state <= "LeftColumn2";

current_state <= "Transition1";

end

"LeftColumn2" : begin

temp_spi_data <= 8'b00010000;

after_state <= "SetDC";

current_state <= "Transition1";

end

"SetDC" : begin

temp_dc <= 1'b1;

current_state <= after_page_state;

end

"ClearScreen" : begin

for(i = 0; i <= 3 ; i=i+1) begin

for(j = 0; j <= 15 ; j=j+1) begin

current_screen[i][j] <= 8'h20;

end

end

after_update_state <= "WaitRequest";

current_state <= "UpdateScreen";

end

"ReadRegisters" : begin

// Page0

current_screen[0][0]<=slv_reg0[7:0];

current_screen[0][1]<=slv_reg0[15:8];

current_screen[0][2]<=slv_reg0[23:16];

current_screen[0][3]<=slv_reg0[31:24];                                       

current_screen[0][4]<=slv_reg1[7:0];

current_screen[0][5]<=slv_reg1[15:8];

current_screen[0][6]<=slv_reg1[23:16];

current_screen[0][7]<=slv_reg1[31:24];                                                                                              

current_screen[0][8]<=slv_reg2[7:0];   

current_screen[0][9]<=slv_reg2[15:8];  

current_screen[0][10]<=slv_reg2[23:16];

current_screen[0][11]<=slv_reg2[31:24];                                                    

current_screen[0][12]<=slv_reg3[7:0];

current_screen[0][13]<=slv_reg3[15:8];  

current_screen[0][14]<=slv_reg3[23:16];

current_screen[0][15]<=slv_reg3[31:24];

//Page1                   

current_screen[1][0]<=slv_reg4[7:0];

current_screen[1][1]<=slv_reg4[15:8];

current_screen[1][2]<=slv_reg4[23:16];

current_screen[1][3]<=slv_reg4[31:24];                                                    

current_screen[1][4]<=slv_reg5[7:0];

current_screen[1][5]<=slv_reg5[15:8];

current_screen[1][6]<=slv_reg5[23:16];

current_screen[1][7]<=slv_reg5[31:24];                                                         

current_screen[1][8]<=slv_reg6[7:0];

current_screen[1][9]<=slv_reg6[15:8];

current_screen[1][10]<=slv_reg6[23:16];

current_screen[1][11]<=slv_reg6[31:24];                                                        

current_screen[1][12]<=slv_reg7[7:0];

current_screen[1][13]<=slv_reg7[15:8];  

current_screen[1][14]<=slv_reg7[23:16];

current_screen[1][15]<=slv_reg7[31:24];

//Page2                    

current_screen[2][0]<=slv_reg8[7:0];

current_screen[2][1]<=slv_reg8[15:8];

current_screen[2][2]<=slv_reg8[23:16];

current_screen[2][3]<=slv_reg8[31:24];                                                    

current_screen[2][4]<=slv_reg9[7:0];

current_screen[2][5]<=slv_reg9[15:8];

current_screen[2][6]<=slv_reg9[23:16];

current_screen[2][7]<=slv_reg9[31:24];                                                    

current_screen[2][8]<=slv_reg10[7:0];

current_screen[2][9]<=slv_reg10[15:8];

current_screen[2][10]<=slv_reg10[23:16];

current_screen[2][11]<=slv_reg10[31:24];                                                    

current_screen[2][12]<=slv_reg11[7:0];

current_screen[2][13]<=slv_reg11[15:8];  

current_screen[2][14]<=slv_reg11[23:16];

current_screen[2][15]<=slv_reg11[31:24];

//Page3                    

current_screen[3][0]<=slv_reg12[7:0];

current_screen[3][1]<=slv_reg12[15:8];

current_screen[3][2]<=slv_reg12[23:16];

current_screen[3][3]<=slv_reg12[31:24];                                                         

current_screen[3][4]<=slv_reg13[7:0];

current_screen[3][5]<=slv_reg13[15:8];

current_screen[3][6]<=slv_reg13[23:16];

current_screen[3][7]<=slv_reg13[31:24];                                                    

current_screen[3][8]<=slv_reg14[7:0];

current_screen[3][9]<=slv_reg14[15:8];

current_screen[3][10]<=slv_reg14[23:16];

current_screen[3][11]<=slv_reg14[31:24];                                                                                             

current_screen[3][12]<=slv_reg15[7:0];

current_screen[3][13]<=slv_reg15[15:8];  

current_screen[3][14]<=slv_reg15[23:16];

current_screen[3][15]<=slv_reg15[31:24];

after_update_state <= "WaitRequest";

current_state <= "UpdateScreen";

end

//UpdateScreen State

//1. Gets ASCII value from current_screen at the current page and the current spot of the page

//2. If on the last character of the page transition update the page number, if on the last page(3)

// then the updateScreen go to "after_update_state" after

"UpdateScreen" : begin

temp_char <= current_screen[temp_page][temp_index];

if(temp_index == 'd15) begin

temp_index <= 'd0;

temp_page <= temp_page + 1'b1;

after_char_state <= "ClearDC";

if(temp_page == 2'b11) begin

after_page_state <= after_update_state;

clear_screen_i<=1'b0;

end

else begin

after_page_state <= "UpdateScreen";

end

end

else begin

temp_index <= temp_index + 1'b1;

after_char_state <= "UpdateScreen";

end

current_state <= "SendChar1";

end

//Send Character States

//1. Sets the Address to ASCII value of char with the counter appended to the end

//2. Waits a clock for the data to get ready by going to ReadMem and ReadMem2 states

//3. Send the byte of data given by the block Ram

//4. Repeat 7 more times for the rest of the character bytes

"SendChar1" : begin

temp_addr <= {temp_char, 3'b000};

after_state <= "SendChar2";

current_state <= "ReadMem";

end

"SendChar2" : begin

temp_addr <= {temp_char, 3'b001};

after_state <= "SendChar3";

current_state <= "ReadMem";

end

"SendChar3" : begin

temp_addr <= {temp_char, 3'b010};

after_state <= "SendChar4";

current_state <= "ReadMem";

end

"SendChar4" : begin

temp_addr <= {temp_char, 3'b011};

after_state <= "SendChar5";

current_state <= "ReadMem";

end

"SendChar5" : begin

temp_addr <= {temp_char, 3'b100};

after_state <= "SendChar6";

current_state <= "ReadMem";

end

"SendChar6" : begin

temp_addr <= {temp_char, 3'b101};

after_state <= "SendChar7";

current_state <= "ReadMem";

end

"SendChar7" : begin

temp_addr <= {temp_char, 3'b110};

after_state <= "SendChar8";

current_state <= "ReadMem";

end

"SendChar8" : begin

temp_addr <= {temp_char, 3'b111};

after_state <= after_char_state;

current_state <= "ReadMem";

end

"ReadMem" : begin

current_state <= "ReadMem2";

end

"ReadMem2" : begin

temp_spi_data <= temp_dout;

current_state <= "Transition1";

end

// SPI transitions

// 1. Set SPI_EN to 1

// 2. Waits for SpiCtrl to finish

// 3. Goes to clear state (Transition5)

"Transition1" : begin

temp_spi_en <= 1'b1;

current_state <= "Transition2";

end

"Transition2" : begin

if(temp_spi_fin == 1'b1) begin

current_state <= "Transition5";

end

end

// Delay Transitions

// 1. Set DELAY_EN to 1

// 2. Waits for Delay to finish

// 3. Goes to Clear state (Transition5)

"Transition3" : begin

temp_delay_en <= 1'b1;

current_state <= "Transition4";

end

"Transition4" : begin

if(temp_delay_fin == 1'b1) begin

current_state <= "Transition5";

end

end

// Clear transition

// 1. Sets both DELAY_EN and SPI_EN to 0

// 2. Go to after state

"Transition5" : begin

temp_spi_en <= 1'b0;

temp_delay_en <= 1'b0;

current_state <= after_state;

end

default : current_state <= "Idle";

endcase

end

end

// Internal reset generator

always @(posedge S_AXI_ACLK) begin

if (RST_IN == 1'b1)

count<=count+1'b1;

if (count == 12'hFFF) begin

RST_internal <=1'b0;

end

end

endmodule

Step3:添加一个 SPI控制器源码 SpiCtrl.v文件，代码如下所示：

`timescale 1ns / 1ps

//////////////////////////////////////////////////////////////////////////////////

//

//

//

//

//

// Create Date:    12:12:51 08/04/2014

// Module Name:    SpiCtrl

// Project Name:  ZedboardOLED

// Target Devices: Zynq

// Tool versions:  Vivado 14.2 (64-bits)

// Description: Spi block that sends SPI data formatted SCLK active low with

//  SDO changing on the falling edge

//

// Revision: 1.0 - SPI completed

// Revision 0.01 - File Created

//

//////////////////////////////////////////////////////////////////////////////////

module SpiCtrl(

CLK,

RST,

SPI_EN,

SPI_DATA,

SDO,

SCLK,

SPI_FIN

);

// ===========================================================================

// Port Declarations

// ===========================================================================

input CLK;

input RST;

input SPI_EN;

input [7:0] SPI_DATA;

output SDO;

output SCLK;

output SPI_FIN;

// ===========================================================================

//   Parameters, Regsiters, and Wires

// ===========================================================================

wire  SDO, SCLK, SPI_FIN;

reg [39:0] current_state = "Idle"; // Signal for state machine

reg [7:0] shift_register = 8'h00; // Shift register to shift out SPI_DATA saved when SPI_EN was set

reg [3:0] shift_counter = 4'h0; // Keeps track how many bits were sent

wire clk_divided; // Used as SCLK

reg [4:0] counter = 5'b00000; // Count clocks to be used to divide CLK

reg temp_sdo = 1'b1; // Tied to SDO

reg falling = 1'b0; // signal indicating that the clk has just fell

// ===========================================================================

// Implementation

// ===========================================================================

assign clk_divided = ~counter[4];

assign SCLK = clk_divided;

assign SDO = temp_sdo;

assign SPI_FIN = (current_state == "Done") ? 1'b1 : 1'b0;

//  State Machine

always @(posedge CLK) begin

if(RST == 1'b1) begin // Synchronous RST

current_state <= "Idle";

end

else begin

case(current_state)

// Wait for SPI_EN to go high

"Idle" : begin

if(SPI_EN == 1'b1) begin

current_state <= "Send";

end

end

// Start sending bits, transition out when all bits are sent and SCLK is high

"Send" : begin

if(shift_counter == 4'h8 && falling == 1'b0) begin

current_state <= "Done";

end

end

// Finish SPI transimission wait for SPI_EN to go low

"Done" : begin

if(SPI_EN == 1'b0) begin

current_state <= "Idle";

end

end

default : current_state <= "Idle";

endcase

end

end

//  End of State Machine

//  Clock Divider

always @(posedge CLK) begin

//  start clock counter when in send state

if(current_state == "Send") begin

counter <= counter + 1'b1;

end

//  reset clock counter when not in send state

else begin

counter <= 5'b00000;

end

end

//  End Clock Divider

//  SPI_SEND_BYTE,  sends SPI data formatted SCLK active low with SDO changing on the falling edge

always @(posedge CLK) begin

if(current_state == "Idle") begin

shift_counter <= 4'h0;

// keeps placing SPI_DATA into shift_register so that when state goes to send it has the latest SPI_DATA

shift_register <= SPI_DATA;

temp_sdo <= 1'b1;

end

else if(current_state == "Send") begin

//  if on the falling edge of Clk_divided

if(clk_divided == 1'b0 && falling == 1'b0) begin

//  Indicate that it is passed the falling edge

falling <= 1'b1;

// send out the MSB

temp_sdo <= shift_register[7];

//  Shift through SPI_DATA

shift_register <= {shift_register[6:0],1'b0};

//  Keep track of what bit it is on

shift_counter <= shift_counter + 1'b1;

end

//  on SCLK high reset the falling flag

else if(clk_divided == 1'b1) begin

falling <= 1'b0;

end

end

end

endmodule

这是一个很好用的SPI控制器，只要通过设置 SPI_EN,SPI_DATA,信号就能发送数据了，这个代码初学者可以当作一个verilog的例子学习下，仔细分析下SPI的工作时序。

Step4:添加一个毫秒延迟模块 Delay.v文件

`timescale 1ns / 1ps

//////////////////////////////////////////////////////////////////////////////////

//

//  

//

//

//

// Create Date:    12:12:51 08/04/2014

// Module Name:    Delay

// Project Name:  ZedboardOLED

// Target Devices: Zynq

// Tool versions:  Vivado 14.2 (64-bits)

// Description:    Creates a delay of DELAY_MS ms

//

// Revision: 1.0

// Revision 0.01 - File Created

//

//////////////////////////////////////////////////////////////////////////////////

module Delay(

CLK,

RST,

DELAY_MS,

DELAY_EN,

DELAY_FIN

);

// ===========================================================================

// Port Declarations

// ===========================================================================

input CLK;

input RST;

input [11:0] DELAY_MS;

input DELAY_EN;

output DELAY_FIN;

// ===========================================================================

//   Parameters, Regsiters, and Wires

// ===========================================================================

wire DELAY_FIN;

reg [31:0] current_state = "Idle"; // Signal for state machine

reg [16:0] clk_counter = 17'b00000000000000000; // Counts up on every rising edge of CLK

reg [11:0] ms_counter = 12'h000; // Counts up when clk_counter = 100,000

// ===========================================================================

// Implementation

// ===========================================================================

assign DELAY_FIN = (current_state == "Done" && DELAY_EN == 1'b1) ? 1'b1 : 1'b0;

//  State Machine

always @(posedge CLK) begin

// When RST is asserted switch to idle (synchronous)

if(RST == 1'b1) begin

current_state <= "Idle";

end

else begin

case(current_state)

"Idle" : begin

// Start delay on DELAY_EN

if(DELAY_EN == 1'b1) begin

current_state <= "Hold";

end

end

"Hold" : begin

// Stay until DELAY_MS has occured

if(ms_counter == DELAY_MS) begin

current_state <= "Done";

end

end

"Done" : begin

// Wait until DELAY_EN is deasserted to go to IDLE

if(DELAY_EN == 1'b0) begin

current_state <= "Idle";

end

end

default : current_state <= "Idle";

endcase

end

end

//  End State Machine

// Creates ms_counter that counts at 1KHz

// CLK_DIV

always @(posedge CLK) begin

if(current_state == "Hold") begin

if(clk_counter == 17'b11000011010100000) begin // 100,000

clk_counter <= 17'b00000000000000000;

ms_counter <= ms_counter + 1'b1; // increments at 1KHz

end

else begin

clk_counter <= clk_counter + 1'b1;

end

end

else begin // If not in the hold state reset counters

clk_counter <= 17'b00000000000000000;

ms_counter <= 12'h000;

end

end

endmodule

Step5:添加一个Block  ROM IP,按下图进行设置。ROM的coe文件可在我们提供的源代码程序包中获得。

Step6:修改完成后重新封装一次自定义IP

Step7:单击NEXT

Step8:和第一次不同，这次选择第一个单选框然后单击NEXT

Step9:选择第一个单选框，然后单击NEXT

Step10:点击Overwrite

Step11:点击Finish 到此自定义IP结束

15.3 OLED硬件控制器关键状态机

always @(posedge S_AXI_ACLK) begin

if(RST_IN == 1'b1) begin

current_state <= "Idle";

temp_res <= 1'b0;

end

else begin

temp_res <= 1'b1;

case(current_state)

// Idle State

"Idle" : begin

if(init_first_r == 1'b1) begin

temp_dc <= 1'b0; // DC= 0 "Commands" , DC=1 "Data"

current_state <= "VddOn";

init_first_r <= 1'b0; // Don't go over the initialization more than once

end

else begin

current_state <="WaitRequest";

end

end

// Initialization Sequence

// This should be done only one time when Zedboard starts

"VddOn" : begin // turn the power on the logic of the display

temp_vdd <= 1'b0; // remember the power FET transistor for VDD is active low

current_state <= "Wait1";

end

// 3

"Wait1" : begin

after_state <= "DispOff";

current_state <= "Transition3";

end

// 4

"DispOff" : begin

temp_spi_data <= 8'hAE; // 0xAE= Set Display OFF

after_state <= "SetClockDiv1";

current_state <= "Transition1";

end

// 5

"SetClockDiv1" : begin  

temp_spi_data <= 8'hD5; //0xD5

after_state <= "SetClockDiv2";

current_state <= "Transition1";

end

// 6

"SetClockDiv2" : begin

temp_spi_data <= 8'h80; // 0x80

after_state <= "MultiPlex1";

current_state <= "Transition1";

end

// 7

"MultiPlex1" : begin  

temp_spi_data <= 8'hA8; //0xA8

after_state <= "MultiPlex2";

current_state <= "Transition1";

end

// 8

"MultiPlex2" : begin

temp_spi_data <= 8'h1F; // 0x1F

after_state <= "ChargePump1";

current_state <= "Transition1";

end

// 9

"ChargePump1" : begin  //  Access Charge Pump Setting

temp_spi_data <= 8'h8D; //0x8D

after_state <= "ChargePump2";

current_state <= "Transition1";

end

// 10

"ChargePump2" : begin //  Enable Charge Pump

temp_spi_data <= 8'h14; // 0x14

after_state <= "PreCharge1";

current_state <= "Transition1";

end

// 11

"PreCharge1" : begin // Access Pre-charge Period Setting

temp_spi_data <= 8'hD9; // 0xD9

after_state <= "PreCharge2";

current_state <= "Transition1";

end

// 12

"PreCharge2" : begin //Set the Pre-charge Period

temp_spi_data <= 8'hFF; // 0xF1

after_state <= "VCOMH1";

current_state <= "Transition1";

end

// 13

"VCOMH1" : begin //Set the Pre-charge Period

temp_spi_data <= 8'hDB; // 0xF1

after_state <= "VCOMH2";

current_state <= "Transition1";

end

// 14

"VCOMH2" : begin //Set the Pre-charge Period

temp_spi_data <= 8'h40; // 0xF1

after_state <= "DispContrast1";

current_state <= "Transition1";

end

// 15

"DispContrast1" : begin //Set Contrast Control for BANK0

temp_spi_data <= 8'h81; // 0x81

after_state <= "DispContrast2";

current_state <= "Transition1";

end

// 16

"DispContrast2" : begin

temp_spi_data <= 8'hF1; // 0x0F

after_state <= "InvertDisp1";

current_state <= "Transition1";

end

// 17

"InvertDisp1" : begin

temp_spi_data <= 8'hA0; // 0xA1

after_state <= "InvertDisp2";

current_state <= "Transition1";

end

// 18

"InvertDisp2" : begin

temp_spi_data <= 8'hC0; // 0xC0

after_state <= "ComConfig1";

current_state <= "Transition1";

end

// 19

"ComConfig1" : begin

temp_spi_data <= 8'hDA; // 0xDA

after_state <= "ComConfig2";

current_state <= "Transition1";

end

// 20

"ComConfig2" : begin

temp_spi_data <= 8'h02; // 0x02

after_state <= "VbatOn";

current_state <= "Transition1";

end

// 21

"VbatOn" : begin

temp_vbat <= 1'b0;

current_state <= "Wait3";

end

// 22

"Wait3" : begin

after_state <= "ResetOn";

current_state <= "Transition3";

end

// 23

"ResetOn" : begin

temp_res <= 1'b0;

current_state <= "Wait2";

end

// 24

"Wait2" : begin

after_state <= "ResetOff";

current_state <= "Transition3";

end

// 25

"ResetOff" : begin

temp_res <= 1'b1;

current_state <= "WaitRequest";

end

// ************ END Initialization sequence but without turnning the dispay on ************

// Main state

"WaitRequest" : begin

if(Display_c == 1'b1) begin

current_state <= "ClearDC";

after_page_state <= "ReadRegisters";

temp_page <= 2'b00;

end

else if ((Clear_c==1'b1) || (clear_screen_i == 1'b1)) begin

current_state <= "ClearDC";

after_page_state <= "ClearScreen";

temp_page <= 2'b00;

end

else begin

current_state<="WaitRequest"; // keep looping in the WaitRequest state untill you receive a command

if ((clear_screen_i == 1'b0) && (ready ==1'b0)) begin  // this part is only executed once, on start-up

temp_spi_data <= 8'hAF; // 0xAF // Dispaly ON

after_state <= "WaitRequest";

current_state <= "Transition1";

temp_dc<=1'b0;

ready <= 1'b1;

end

end

end

//Update Page states

//1. Sets DC to command mode

//2. Sends the SetPage Command

//3. Sends the Page to be set to

//4. Sets the start pixel to the left column

//5. Sets DC to data mode

"ClearDC" : begin

temp_dc <= 1'b0;

current_state <= "SetPage";

end

"SetPage" : begin

temp_spi_data <= 8'b00100010;

after_state <= "PageNum";

current_state <= "Transition1";

end

"PageNum" : begin

temp_spi_data <= {6'b000000,temp_page};

after_state <= "LeftColumn1";

current_state <= "Transition1";

end

"LeftColumn1" : begin

temp_spi_data <= 8'b00000000;

after_state <= "LeftColumn2";

current_state <= "Transition1";

end

"LeftColumn2" : begin

temp_spi_data <= 8'b00010000;

after_state <= "SetDC";

current_state <= "Transition1";

end

"SetDC" : begin

temp_dc <= 1'b1;

current_state <= after_page_state;

end

"ClearScreen" : begin

for(i = 0; i <= 3 ; i=i+1) begin

for(j = 0; j <= 15 ; j=j+1) begin

current_screen[i][j] <= 8'h20;

end

end

after_update_state <= "WaitRequest";

current_state <= "UpdateScreen";

end

"ReadRegisters" : begin

// Page0

current_screen[0][0]<=slv_reg0[7:0];

current_screen[0][1]<=slv_reg0[15:8];

current_screen[0][2]<=slv_reg0[23:16];

current_screen[0][3]<=slv_reg0[31:24];                                       

current_screen[0][4]<=slv_reg1[7:0];

current_screen[0][5]<=slv_reg1[15:8];

current_screen[0][6]<=slv_reg1[23:16];

current_screen[0][7]<=slv_reg1[31:24];                                                                                              

current_screen[0][8]<=slv_reg2[7:0];   

current_screen[0][9]<=slv_reg2[15:8];  

current_screen[0][10]<=slv_reg2[23:16];

current_screen[0][11]<=slv_reg2[31:24];                                                    

current_screen[0][12]<=slv_reg3[7:0];

current_screen[0][13]<=slv_reg3[15:8];  

current_screen[0][14]<=slv_reg3[23:16];

current_screen[0][15]<=slv_reg3[31:24];

//Page1                   

current_screen[1][0]<=slv_reg4[7:0];

current_screen[1][1]<=slv_reg4[15:8];

current_screen[1][2]<=slv_reg4[23:16];

current_screen[1][3]<=slv_reg4[31:24];                                                    

current_screen[1][4]<=slv_reg5[7:0];

current_screen[1][5]<=slv_reg5[15:8];

current_screen[1][6]<=slv_reg5[23:16];

current_screen[1][7]<=slv_reg5[31:24];                                                         

current_screen[1][8]<=slv_reg6[7:0];

current_screen[1][9]<=slv_reg6[15:8];

current_screen[1][10]<=slv_reg6[23:16];

current_screen[1][11]<=slv_reg6[31:24];                                                        

current_screen[1][12]<=slv_reg7[7:0];

current_screen[1][13]<=slv_reg7[15:8];  

current_screen[1][14]<=slv_reg7[23:16];

current_screen[1][15]<=slv_reg7[31:24];

//Page2                    

current_screen[2][0]<=slv_reg8[7:0];

current_screen[2][1]<=slv_reg8[15:8];

current_screen[2][2]<=slv_reg8[23:16];

current_screen[2][3]<=slv_reg8[31:24];                                                    

current_screen[2][4]<=slv_reg9[7:0];

current_screen[2][5]<=slv_reg9[15:8];

current_screen[2][6]<=slv_reg9[23:16];

current_screen[2][7]<=slv_reg9[31:24];                                                    

current_screen[2][8]<=slv_reg10[7:0];

current_screen[2][9]<=slv_reg10[15:8];

current_screen[2][10]<=slv_reg10[23:16];

current_screen[2][11]<=slv_reg10[31:24];                                                    

current_screen[2][12]<=slv_reg11[7:0];

current_screen[2][13]<=slv_reg11[15:8];  

current_screen[2][14]<=slv_reg11[23:16];

current_screen[2][15]<=slv_reg11[31:24];

//Page3                    

current_screen[3][0]<=slv_reg12[7:0];

current_screen[3][1]<=slv_reg12[15:8];

current_screen[3][2]<=slv_reg12[23:16];

current_screen[3][3]<=slv_reg12[31:24];                                                         

current_screen[3][4]<=slv_reg13[7:0];

current_screen[3][5]<=slv_reg13[15:8];

current_screen[3][6]<=slv_reg13[23:16];

current_screen[3][7]<=slv_reg13[31:24];                                                    

current_screen[3][8]<=slv_reg14[7:0];

current_screen[3][9]<=slv_reg14[15:8];

current_screen[3][10]<=slv_reg14[23:16];

current_screen[3][11]<=slv_reg14[31:24];                                                                                             

current_screen[3][12]<=slv_reg15[7:0];

current_screen[3][13]<=slv_reg15[15:8];  

current_screen[3][14]<=slv_reg15[23:16];

current_screen[3][15]<=slv_reg15[31:24];

after_update_state <= "WaitRequest";

current_state <= "UpdateScreen";

end

//UpdateScreen State

//1. Gets ASCII value from current_screen at the current page and the current spot of the page

//2. If on the last character of the page transition update the page number, if on the last page(3)

// then the updateScreen go to "after_update_state" after

"UpdateScreen" : begin

temp_char <= current_screen[temp_page][temp_index];

if(temp_index == 'd15) begin

temp_index <= 'd0;

temp_page <= temp_page + 1'b1;

after_char_state <= "ClearDC";

if(temp_page == 2'b11) begin

after_page_state <= after_update_state;

clear_screen_i<=1'b0;

end

else begin

after_page_state <= "UpdateScreen";

end

end

else begin

temp_index <= temp_index + 1'b1;

after_char_state <= "UpdateScreen";

end

current_state <= "SendChar1";

end

//Send Character States

//1. Sets the Address to ASCII value of char with the counter appended to the end

//2. Waits a clock for the data to get ready by going to ReadMem and ReadMem2 states

//3. Send the byte of data given by the block Ram

//4. Repeat 7 more times for the rest of the character bytes

"SendChar1" : begin

temp_addr <= {temp_char, 3'b000};

after_state <= "SendChar2";

current_state <= "ReadMem";

end

"SendChar2" : begin

temp_addr <= {temp_char, 3'b001};

after_state <= "SendChar3";

current_state <= "ReadMem";

end

"SendChar3" : begin

temp_addr <= {temp_char, 3'b010};

after_state <= "SendChar4";

current_state <= "ReadMem";

end

"SendChar4" : begin

temp_addr <= {temp_char, 3'b011};

after_state <= "SendChar5";

current_state <= "ReadMem";

end

"SendChar5" : begin

temp_addr <= {temp_char, 3'b100};

after_state <= "SendChar6";

current_state <= "ReadMem";

end

"SendChar6" : begin

temp_addr <= {temp_char, 3'b101};

after_state <= "SendChar7";

current_state <= "ReadMem";

end

"SendChar7" : begin

temp_addr <= {temp_char, 3'b110};

after_state <= "SendChar8";

current_state <= "ReadMem";

end

"SendChar8" : begin

temp_addr <= {temp_char, 3'b111};

after_state <= after_char_state;

current_state <= "ReadMem";

end

"ReadMem" : begin

current_state <= "ReadMem2";

end

"ReadMem2" : begin

temp_spi_data <= temp_dout;

current_state <= "Transition1";

end

// SPI transitions

// 1. Set SPI_EN to 1

// 2. Waits for SpiCtrl to finish

// 3. Goes to clear state (Transition5)

"Transition1" : begin

temp_spi_en <= 1'b1;

current_state <= "Transition2";

end

"Transition2" : begin

if(temp_spi_fin == 1'b1) begin

current_state <= "Transition5";

end

end

// Delay Transitions

// 1. Set DELAY_EN to 1

// 2. Waits for Delay to finish

// 3. Goes to Clear state (Transition5)

"Transition3" : begin

temp_delay_en <= 1'b1;

current_state <= "Transition4";

end

"Transition4" : begin

if(temp_delay_fin == 1'b1) begin

current_state <= "Transition5";

end

end

// Clear transition

// 1. Sets both DELAY_EN and SPI_EN to 0

// 2. Go to after state

"Transition5" : begin

temp_spi_en <= 1'b0;

temp_delay_en <= 1'b0;

current_state <= after_state;

end

default : current_state <= "Idle";

endcase

end

end

// Internal reset generator

always @(posedge S_AXI_ACLK) begin

if (RST_IN == 1'b1)

count<=count+1'b1;

if (count == 12'hFFF) begin

RST_internal <=1'b0;

end

end

这个状态机实现了OLED的通电控制、初始化、以及字符的显示。

15.4 硬件工程搭建

Step1：另外新建一个VIVADO工程，根据自己的开发板正确配置芯片型号。

Step2：在Project manager区中单击Project settings。

Step3：选择IP设置区中的repository manager,将上一节我们封装好的IP的路劲添加进去。

Step:4：单击+号图标，将上一节封装的IP的路劲存放进去，单击OK。

Step5：新建一个BD文件，输入文件名，完成创建。

Step6：向BD文件中添加一个ZYNQ Processing system,根据自身硬件完成IP的配置。

Step7：单击添加IP图标，输入上一节我们自定义IP的模块名，将其添加入BD文件中。

Step8：直接点击Run connection automation，然后单击OK。

Step9：选中SSD1306控制IP的输出端口，按Ctrl+T组合键引出端口。

Step10：右键单击Block文件，文件选择Generate the Output Products。

Step11：右键单击Block文件，选择Create a HDL wrapper，根据Block文件内容产生一个HDL 的顶层文件，并选择让vivado自动完成。

Step12：添加一个约束文件，打开对应自己硬件的原理图，查看OLED部分引脚连接情况。Miz702约束文件如下所示：

set_property PACKAGE_PIN U10 [get_ports DC]

set_property PACKAGE_PIN U9 [get_ports RES]

set_property PACKAGE_PIN AB12 [get_ports SCLK]

set_property PACKAGE_PIN AA12 [get_ports SDIN]

set_property PACKAGE_PIN U11 [get_ports VBAT]

set_property PACKAGE_PIN U12 [get_ports VDD]

set_property IOSTANDARD LVCMOS33 [get_ports DC]

set_property IOSTANDARD LVCMOS33 [get_ports RES]

set_property IOSTANDARD LVCMOS33 [get_ports SCLK]

set_property IOSTANDARD LVCMOS33 [get_ports SDIN]

set_property IOSTANDARD LVCMOS33 [get_ports VBAT]

set_property IOSTANDARD LVCMOS33 [get_ports VDD]

set_property PACKAGE_PIN N17 [get_ports VDD]

其他型号开发板参照对应型号的原理图的OLED部分，修改成对应的引脚即可。

Step13：生成bit文件。

15.5 导入到SDK

Step1:导出硬件。

Step2:新建一个名为OLED_Test的空白工程。

Step3:打开我们提供的源程序包，在第二季，第15章的文件夹中，将SDK所有的文件复制过来。

Step4:展开OLED_Test,在Src下按Ctrl+V将所有文件粘贴过来。

Step5：右击工程，选择Debug as ->Debug configuration。

Step6：选中system Debugger,双击创建一个系统调试。

Step7：设置系统调试。

Step8:单击运行程序按钮运行程序，此时可在OLED上观察到滚动显示我们定义的字符。

15.6 本章小结

本章的方案虽然不及14章的功能强大，但是可以提高CPU的工作效率，充分发挥PL的硬件资源的能力，减轻CPU的负担。

两种方案各有优缺点，前者很好地平衡了PS和PL部分的工作，但是功能单一，只能够显示字符；后者未能合理使用PL资源，但是灵活度高、功能强大。读者可以尝试将两种方案进行融合，取长补短，设计出更优秀的方案。