串口控制led闪烁可调频率
项目gitlab地址： http://120.55.75.228:23080/zhdyz/axi_lite_led
任务需求
电脑端串口调试助手发送指令到PS端串口，PS端根据指令控制PL端LED灯的状态
PL端led灯分别为led0，led1，状态与控制指令如下所示，可通过指令调整频率
实验流程
IP核创建
创建一个如下类型的IP核，类型为AXI_Lite，模式为Slave，使用4个寄存器（最少4个）
然后编辑代码，因为要控制PL端的led0，led1，所以添加端口
添加模块led.v，功能为根据LED_TYPE和FREQ控制led的亮灭和闪烁
`timescale 1ns / 1ps
module led(
input clk,
input rst_n,
input [15:0] LED_TYPE,
input [15:0] FREQ,
output reg led0,
output reg led1
);
//测试用
//wire [15:0] LED_TYPE1;
//assign LED_TYPE1=1;
reg clk1,clk2,clk3,clk4;
reg [31:0]cnt4;
//clk4 = 2HZ
always@(posedge clk or negedge rst_n) begin
if(!rst_n) begin
clk4<=0;
cnt4<=0;
end
else begin
if(cnt4==12499999) begin
cnt4<=0;
clk4<=~clk4;
end
else cnt4<=cnt4+1;
end
end
//clk3 = 1HZ
always@(posedge clk4 or negedge rst_n) begin
if(!rst_n)
clk3<=0;
else
clk3<=~clk3;
end
//clk2 = 0.5HZ
always@(posedge clk3 or negedge rst_n) begin
if(!rst_n)
clk2<=0;
else
clk2<=~clk2;
end
//clk1 = 0.25HZ
always@(posedge clk2 or negedge rst_n) begin
if(!rst_n)
clk1<=0;
else
clk1<=~clk1;
end
always@(posedge clk or negedge rst_n) begin
if(!rst_n) begin
led0<=1;
led1<=1;
end
else begin
if(LED_TYPE==0) begin
led0<=0;
led1<=0;
end
else if(LED_TYPE==1) begin
led0<=1;
led1<=0;
end
else if(LED_TYPE==2) begin
led0<=0;
led1<=1;
end
else if(LED_TYPE==3) begin
led0<=1;
led1<=1;
end
else if(LED_TYPE==4) begin
if(FREQ==1) begin
if(clk1==1) begin
led0<=1;
led1<=1;
end
else begin
led0<=0;
led1<=0;
end
end
else if(FREQ==2) begin
if(clk2==1) begin
led0<=1;
led1<=1;
end
else begin
led0<=0;
led1<=0;
end
end
else if(FREQ==4) begin
if(clk3==1) begin
led0<=1;
led1<=1;
end
else begin
led0<=0;
led1<=0;
end
end
else if(FREQ==8) begin
if(clk4==1) begin
led0<=1;
led1<=1;
end
else begin
led0<=0;
led1<=0;
end
end
end
else begin
led0<=led0;
led1<=led1;
end
end
end
然后在AXI IP核内实例化这个模块，4个寄存器中只使用了寄存器0（slv_reg0），其中LED_TYPE为寄存器0的31-16位，FREQ为寄存器0的15-0位，即PS端向寄存器0写入值相当于对LED_TYPE和FREQ两个参数赋值
AXI IP核设计好后进行封装
然后在目录中找到Makefile进行替换，具体看文章 头文件xparameters.h无法找到
同时IP核封装好后会自动生成axi_led_control.h头文件供后面Vitis编程使用，内容如下
#ifndef AXI_LED_CONTROL_H
#define AXI_LED_CONTROL_H
/****************** Include Files ********************/
#include "xil_types.h"
#include "xstatus.h"
#define AXI_LED_CONTROL_S00_AXI_SLV_REG0_OFFSET 0
#define AXI_LED_CONTROL_S00_AXI_SLV_REG1_OFFSET 4
#define AXI_LED_CONTROL_S00_AXI_SLV_REG2_OFFSET 8
#define AXI_LED_CONTROL_S00_AXI_SLV_REG3_OFFSET 12
/**************************** Type Definitions *****************************/
/**
*
* Write a value to a AXI_LED_CONTROL register. A 32 bit write is performed.
* If the component is implemented in a smaller width, only the least
* significant data is written.
*
* @param BaseAddress is the base address of the AXI_LED_CONTROLdevice.
* @param RegOffset is the register offset from the base to write to.
* @param Data is the data written to the register.
*
* @return None.
*
* @note
* C-style signature:
* void AXI_LED_CONTROL_mWriteReg(u32 BaseAddress, unsigned RegOffset, u32 Data)
*
*/
#define AXI_LED_CONTROL_mWriteReg(BaseAddress, RegOffset, Data) \
Xil_Out32((BaseAddress) + (RegOffset), (u32)(Data))
/**
*
* Read a value from a AXI_LED_CONTROL register. A 32 bit read is performed.
* If the component is implemented in a smaller width, only the least
* significant data is read from the register. The most significant data
* will be read as 0.
*
* @param BaseAddress is the base address of the AXI_LED_CONTROL device.
* @param RegOffset is the register offset from the base to write to.
*
* @return Data is the data from the register.
*
* @note
* C-style signature:
* u32 AXI_LED_CONTROL_mReadReg(u32 BaseAddress, unsigned RegOffset)
*
*/
#define AXI_LED_CONTROL_mReadReg(BaseAddress, RegOffset) \
Xil_In32((BaseAddress) + (RegOffset))
/************************** Function Prototypes ****************************/
/**
*
* Run a self-test on the driver/device. Note this may be a destructive test if
* resets of the device are performed.
*
* If the hardware system is not built correctly, this function may never
* return to the caller.
*
* @param baseaddr_p is the base address of the AXI_LED_CONTROL instance to be worked on.
*
* @return
*
* - XST_SUCCESS if all self-test code passed
* - XST_FAILURE if any self-test code failed
*
* @note Caching must be turned off for this function to work.
* @note Self test may fail if data memory and device are not on the same bus.
*
*/
XStatus AXI_LED_CONTROL_Reg_SelfTest(void * baseaddr_p);
#endif // AXI_LED_CONTROL_H
Block Design
创建新项目，打开Block Design，创建Zynq IP核，配置好ddr型号和启用UART，其他保持默认
然后添加刚才创建的IP核，连线，如下图所示
封装Block Design，将led0，led1分配管脚，生成bitstream，然后导出xsa
Vitis设计
导入xsa，新建main.c，内容如下，实现了PS端串口收发指令来向寄存器写入参数
#include "stdio.h"
#include "xparameters.h"
#include "xil_printf.h"
#include "axi_led_control.h"
#include "xil_io.h"
#include "sleep.h"
#define LED_IP_BASEADDR XPAR_AXI_LED_CONTROL_0_S00_AXI_BASEADDR //LED IP基地址
#define LED_IP_REG0 AXI_LED_CONTROL_S00_AXI_SLV_REG0_OFFSET //LED IP寄存器地址0
//main函数
int main()
{
//范围为0,1,2,3,4，其余无效
int led_type=3;
//范围为1,2,4,8，其余无效
int freq=1;
//32位指令
int instruction;
xil_printf("LED User IP Test!\r\n");
while(1){
xil_printf("input a number to control led\r\n");
scanf("%d",&led_type);
if(led_type==1||led_type==2||led_type==3){
instruction=(led_type<<16)+freq;
AXI_LED_CONTROL_mWriteReg(LED_IP_BASEADDR,LED_IP_REG0,instruction);//调用API向寄存器写入值
}
else if(led_type==4){
xil_printf("input a number to control freqence\r\n");
scanf("%d",&freq);
instruction=(led_type<<16)+freq;
AXI_LED_CONTROL_mWriteReg(LED_IP_BASEADDR,LED_IP_REG0,instruction);//调用API向寄存器写入值
}
}
}
测试结果
串口调试助手输入数字指令
0.5Hz闪烁
1Hz闪烁
2Hz闪烁
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