版本：Vivado2020.2（Vitis）
任务：以 VDAM IP 为核心实现 VGA 彩条图像显示，同时支持输出分辨率可调。
（PS 端写入彩条数据到 DDR 通过 VDMA 读取出来输出给 VGA 进行显示）
目录
一、介绍
本例基于上次例程进行优化，实现 VGA 彩条图像显示的同时，支持输出分辨率可调，以满足不同视频分辨率的需求。
参考了正点原子的例程，但有所不同，他是通过 AXI GPIO 读取 LCD设备型号 ID 判断并配置分辨率。而我使用 VGA 进行显示且大多数 VGA 显示器都支持多种分辨率输入，对于不同型号 VGA 显示器各有差别，所以就直接通过PS端主动调节输出分辨率即可。本次只设计三种 VGA 分辨率可调：640*480@60Hz、800x600@60Hz、1280*720@60Hz。
二、硬件设计
（1）整体系统框架
框架和 “笔记十八”里面一致，区别在于时钟IP配置为可动态调节，PS端通过 GP 接口可对其输出时钟进行配置，此外还将 RGB888_to_444 模块进行优化并封装为带 vid_io_rtl 类型接口输入的 IP核，使BD设计视图更加简洁清晰。
基本原理、相关 IP 介绍、系统框架搭建参考：ZYNQ笔记（十八）：VDMA VGA彩条显示
（2）VTC 配置
在之前配置的基础上添加 AXI-Lite 接口，这样 PS 端可以通过 GP 接口对其进行配置
（3）Clock 时钟配置
不同分辨率像素时钟不同，所以需要对应输出不同频率的时钟，Clock IP 启用动态配置功能，可以看到 IP 增加了一组 AXI-Lite 接口。这样 PS 端可以通过 GP 接口对其输出时钟频率进行重新配置。
（4）RGB888_to_444
之前的 RGB888_to_444 是作为模块添加到 bd设计中，将Video Out 输出的 RGB888 数据进行截位与拼接，输出 RGB444 格式数据。为了让 bd 设计更加简洁规范，把它封装为有关带 vid_io_rtl 类型接口输入的 IP 核，以连接 Video Out IP 的视频信号接口。
`timescale 1ns / 1ps
module RGB888_to_444(
input wire vid_hsync, // 输入行同步信号
input wire vid_vsync, // 输入场同步信号
input wire [23:0] RGB888, // 24位RGB888输入 (R[23:16], G[15:8], B[7:0])
output wire hsync, // 输出行同步信号
output wire vsync, // 输出场同步信号
output wire [11:0] RGB444 // 12位RGB444输出 (R[11:8], G[7:4], B[3:0])
);
assign vsync = vid_vsync;
assign hsync = vid_hsync;
assign RGB444 = {RGB888[23:20], RGB888[15:12], RGB888[7:4]}; // 截取RGB888各通道的高4位，组合成RGB444
endmoduleIP 封装以及接口定义参考：ZYNQ笔记（十七）：IP核封装与接口定义
（5）连线
完成关键信号连线，连线情况如图所示：
再运行自动连接，最后整体 bd 设计部分如图所示：设计检查、Generate Output Products、 Create HDL Wrapper、管脚约束、Gnerate Bitstream、Export Hardware（包含比特流文件）、启动Vitis
三、软件设计
（1）clk_wiz
"xclk_wiz.h" 是Vitis提供的关于时钟IP核相关的库函数头文，"clk_wiz.h" 是自己编写的用于定义时钟相关寄存器的头文件。
clk_wiz.h :
#ifndef CLK_WIZ_H_
#define CLK_WIZ_H_
#include "xil_types.h"
#define CLK_SR_OFFSET 0x04 //Status Register
#define CLK_CFG0_OFFSET 0x200 //Clock Configuration Register 0
#define CLK_CFG2_OFFSET 0x208 //Clock Configuration Register 2
#define CLK_CFG23_OFFSET 0x25C //Clock Configuration Register 23
void clk_wiz_cfg(u32 clk_device_id,double freq);
#endif /* CLK_WIZ_H_ */clk_wiz.c :
#include "xclk_wiz.h"
#include "clk_wiz.h"
#include "xparameters.h"
#define CLK_WIZ_IN_FREQ 100 //时钟IP核输入100Mhz
XClk_Wiz clk_wiz_inst; //时钟IP核驱动实例
//时钟IP核动态重配置
//参数1:时钟IP核的器件ID
//参数2:时钟IP核输出的时钟 单位：MHz
void clk_wiz_cfg(u32 clk_device_id,double freq)
{
double div_factor = 0;
u32 div_factor_int = 0,dviv_factor_frac=0;
u32 clk_divide = 0;
u32 status = 0;
//初始化XCLK_Wiz
XClk_Wiz_Config *clk_cfg_ptr;
clk_cfg_ptr = XClk_Wiz_LookupConfig(clk_device_id);
XClk_Wiz_CfgInitialize(&clk_wiz_inst,clk_cfg_ptr,clk_cfg_ptr->BaseAddr);
if(freq <= 0)
return;
//配置时钟倍频/分频系数
XClk_Wiz_WriteReg(clk_cfg_ptr->BaseAddr,CLK_CFG0_OFFSET,0x00000a01); //10倍频，1分频
//计算分频系数
div_factor = CLK_WIZ_IN_FREQ * 10 / freq;
div_factor_int = (u32)div_factor;
dviv_factor_frac = (u32)((div_factor - div_factor_int) * 1000);
clk_divide = div_factor_int | (dviv_factor_frac<<8);
//配置分频系数
XClk_Wiz_WriteReg(clk_cfg_ptr->BaseAddr,CLK_CFG2_OFFSET,clk_divide);
//加载重配置的参数
XClk_Wiz_WriteReg(clk_cfg_ptr->BaseAddr,CLK_CFG23_OFFSET,0x00000003);
//获取时钟IP核的状态，判断是否重配置完成
while(1){
status = XClk_Wiz_ReadReg(clk_cfg_ptr->BaseAddr,CLK_SR_OFFSET);
if(status&0x00000001) //Bit0 Locked信号
return ;
}
}（2）display_ctrl
这一部分使用的正点原子的代码，display_ctrl.c 和.h 是用于实现 VTC 配置的，不过做了一些微调（本例没用到GPIO）。同时还有一个 lcd_modes.h 包含不同分辨率格式的时序配置参数，同样适用于 VGA 显示器。代码如下：
display_ctrl.c
/************************************************************************/
/* */
/* display_ctrl.c -- Digilent Display Controller Driver */
/* */
/************************************************************************/
/* Author: Sam Bobrowicz */
/* Copyright 2014, Digilent Inc. */
/************************************************************************/
/* Module Description: */
/* */
/* This module provides an easy to use API for controlling a */
/* Display attached to a Digilent system board via VGA or HDMI. */
/* run-time resolution setting and seamless framebuffer-swapping */
/* for tear-free animation. */
/* */
/* To use this driver, you must have a Xilinx Video Timing */
/* Controller core (vtc), Xilinx axi_vdma core, a Digilent */
/* axi_dynclk core, a Xilinx AXI Stream to Video core, and either */
/* a Digilent RGB2VGA or RGB2DVI core all present in your design. */
/* See the Video in or Display out reference projects for your */
/* system board to see how they need to be connected. Digilent */
/* reference projects and IP cores can be found at */
/* www.github.com/Digilent. */
/* */
/* The following steps should be followed to use this driver: */
/* 1) Create a DisplayCtrl object and pass a pointer to it to */
/* DisplayInitialize. */
/* 2) Call DisplaySetMode to set the desired mode */
/* 3) Call DisplayStart to begin outputting data to the display */
/* 4) To create a seamless animation, draw the next image to a */
/* framebuffer currently not being displayed. Then call */
/* DisplayChangeFrame to begin displaying that frame. */
/* Repeat as needed, only ever modifying inactive frames. */
/* 5) To change the resolution, call DisplaySetMode, followed by */
/* DisplayStart again. */
/* */
/* */
/************************************************************************/
/* Revision History: */
/* */
/* 2/20/2014(SamB): Created */
/* 11/25/2015(SamB): Changed from axi_dispctrl to Xilinx cores */
/* Separated Clock functions into dynclk library */
/* */
/************************************************************************/
/*
* TODO: It would be nice to remove the need for users above this to access
* members of the DisplayCtrl struct manually. This can be done by
* implementing get/set functions for things like video mode, state,
* etc.
*/
/* ------------------------------------------------------------ */
/* Include File Definitions */
/* ------------------------------------------------------------ */
/*
* Uncomment for Debugging messages over UART
*/
//#define DEBUG
#include "display_ctrl.h"
#include "xdebug.h"
#include "xil_io.h"
/* ------------------------------------------------------------ */
/* Procedure Definitions */
/* ------------------------------------------------------------ */
/*** DisplayStop(DisplayCtrl *dispPtr)
**
** Parameters:
** dispPtr - Pointer to the initialized DisplayCtrl struct
**
** Return Value: int
** XST_SUCCESS if successful.
** XST_DMA_ERROR if an error was detected on the DMA channel. The
** Display is still successfully stopped, and the error is
** cleared so that subsequent DisplayStart calls will be
** successful. This typically indicates insufficient bandwidth
** on the AXI Memory-Map Interconnect (VDMA<->DDR)
**
** Description:
** Halts output to the display
**
*/
int DisplayStop(DisplayCtrl *dispPtr)
{
/*
* If already stopped, do nothing
*/
if (dispPtr->state == DISPLAY_STOPPED)
{
return XST_SUCCESS;
}
/*
* Disable the disp_ctrl core, and wait for the current frame to finish (the core cannot stop
* mid-frame)
*/
XVtc_DisableGenerator(&dispPtr->vtc);
/*
* Update Struct state
*/
dispPtr->state = DISPLAY_STOPPED;
//TODO: consider stopping the clock here, perhaps after a check to see if the VTC is finished
return XST_SUCCESS;
}
/* ------------------------------------------------------------ */
/*** DisplayStart(DisplayCtrl *dispPtr)
**
** Parameters:
** dispPtr - Pointer to the initialized DisplayCtrl struct
**
** Return Value: int
** XST_SUCCESS if successful, XST_FAILURE otherwise
**
** Errors:
**
** Description:
** Starts the display.
**
*/
int DisplayStart(DisplayCtrl *dispPtr)
{
XVtc_Timing vtcTiming;
XVtc_SourceSelect SourceSelect;
xdbg_printf(XDBG_DEBUG_GENERAL, "display start entered\n\r");
/*
* If already started, do nothing
*/
if (dispPtr->state == DISPLAY_RUNNING)
{
return XST_SUCCESS;
}
/*
* Configure the vtc core with the display mode timing parameters
*/
vtcTiming.HActiveVideo = dispPtr->vMode.width; /**< Horizontal Active Video Size */
vtcTiming.HFrontPorch = dispPtr->vMode.hps - dispPtr->vMode.width; /**< Horizontal Front Porch Size */
vtcTiming.HSyncWidth = dispPtr->vMode.hpe - dispPtr->vMode.hps; /**< Horizontal Sync Width */
vtcTiming.HBackPorch = dispPtr->vMode.hmax - dispPtr->vMode.hpe + 1; /**< Horizontal Back Porch Size */
vtcTiming.HSyncPolarity = dispPtr->vMode.hpol; /**< Horizontal Sync Polarity */
vtcTiming.VActiveVideo = dispPtr->vMode.height; /**< Vertical Active Video Size */
vtcTiming.V0FrontPorch = dispPtr->vMode.vps - dispPtr->vMode.height; /**< Vertical Front Porch Size */
vtcTiming.V0SyncWidth = dispPtr->vMode.vpe - dispPtr->vMode.vps; /**< Vertical Sync Width */
vtcTiming.V0BackPorch = dispPtr->vMode.vmax - dispPtr->vMode.vpe + 1;; /**< Horizontal Back Porch Size */
vtcTiming.V1FrontPorch = dispPtr->vMode.vps - dispPtr->vMode.height; /**< Vertical Front Porch Size */
vtcTiming.V1SyncWidth = dispPtr->vMode.vpe - dispPtr->vMode.vps; /**< Vertical Sync Width */
vtcTiming.V1BackPorch = dispPtr->vMode.vmax - dispPtr->vMode.vpe + 1;; /**< Horizontal Back Porch Size */
vtcTiming.VSyncPolarity = dispPtr->vMode.vpol; /**< Vertical Sync Polarity */
vtcTiming.Interlaced = 0; /**< Interlaced / Progressive video */
/* Setup the VTC Source Select config structure. */
/* 1=Generator registers are source */
/* 0=Detector registers are source */
memset((void *)&SourceSelect, 0, sizeof(SourceSelect));
SourceSelect.VBlankPolSrc = 1;
SourceSelect.VSyncPolSrc = 1;
SourceSelect.HBlankPolSrc = 1;
SourceSelect.HSyncPolSrc = 1;
SourceSelect.ActiveVideoPolSrc = 1;
SourceSelect.ActiveChromaPolSrc= 1;
SourceSelect.VChromaSrc = 1;
SourceSelect.VActiveSrc = 1;
SourceSelect.VBackPorchSrc = 1;
SourceSelect.VSyncSrc = 1;
SourceSelect.VFrontPorchSrc = 1;
SourceSelect.VTotalSrc = 1;
SourceSelect.HActiveSrc = 1;
SourceSelect.HBackPorchSrc = 1;
SourceSelect.HSyncSrc = 1;
SourceSelect.HFrontPorchSrc = 1;
SourceSelect.HTotalSrc = 1;
XVtc_SelfTest(&(dispPtr->vtc));
XVtc_RegUpdateEnable(&(dispPtr->vtc));
XVtc_SetGeneratorTiming(&(dispPtr->vtc), &vtcTiming);
XVtc_SetSource(&(dispPtr->vtc), &SourceSelect);
/*
* Enable VTC core, releasing backpressure on VDMA
*/
XVtc_EnableGenerator(&dispPtr->vtc);
dispPtr->state = DISPLAY_RUNNING;
return XST_SUCCESS;
}
/* ------------------------------------------------------------ */
/*** DisplayInitialize(DisplayCtrl *dispPtr,u16 vtcId)
**
** Parameters:
** dispPtr - Pointer to the struct that will be initialized
** vtcId - Device ID of the VTC core as found in xparameters.h
**
** Return Value: int
** XST_SUCCESS if successful, XST_FAILURE otherwise
**
** Errors:
**
** Description:
** Initializes the driver struct for use.
**
*/
int DisplayInitialize(DisplayCtrl *dispPtr, u16 vtcId)
{
int Status;
XVtc_Config *vtcConfig;
/*
* Initialize all the fields in the DisplayCtrl struct
*/
dispPtr->state = DISPLAY_STOPPED;
dispPtr->vMode = VMODE_1280x720;//原代码为VMODE_800x480;
/* Initialize the VTC driver so that it's ready to use look up
* configuration in the config table, then initialize it.
*/
vtcConfig = XVtc_LookupConfig(vtcId);
/* Checking Config variable */
if (NULL == vtcConfig) {
return (XST_FAILURE);
}
Status = XVtc_CfgInitialize(&(dispPtr->vtc), vtcConfig, vtcConfig->BaseAddress);
/* Checking status */
if (Status != (XST_SUCCESS)) {
return (XST_FAILURE);
}
return XST_SUCCESS;
}
/* ------------------------------------------------------------ */
/*** DisplaySetMode(DisplayCtrl *dispPtr, const VideoMode *newMode)
**
** Parameters:
** dispPtr - Pointer to the initialized DisplayCtrl struct
** newMode - The VideoMode struct describing the new mode.
**
** Return Value: int
** XST_SUCCESS if successful, XST_FAILURE otherwise
**
** Errors:
**
** Description:
** Changes the resolution being output to the display. If the display
** is currently started, it is automatically stopped (DisplayStart must
** be called again).
**
*/
int DisplaySetMode(DisplayCtrl *dispPtr, const VideoMode *newMode)
{
int Status;
/*
* If currently running, stop
*/
if (dispPtr->state == DISPLAY_RUNNING)
{
Status = DisplayStop(dispPtr);
if (Status != XST_SUCCESS)
{
xdbg_printf(XDBG_DEBUG_GENERAL, "Cannot change mode, unable to stop display %d\r\n", Status);
return XST_FAILURE;
}
}
dispPtr->vMode = *newMode;
return XST_SUCCESS;
}
/*
//获取LCD屏ID
//PG6=R7(M0);PI2=G7(M1);PI7=B7(M2);
//M2:M1:M0
//0 :0 :0 //4.3寸480*272 RGB屏,ID=0X4342
//0 :0 :1 //7寸800*480 RGB屏,ID=0X7084
//0 :1 :0 //7寸1024*600 RGB屏,ID=0X7016
//1 :0 :0 //4.3寸800*480 RGB屏,ID=0X4384
//1 :0 :1 //10.1寸1280*800 RGB屏,ID=0X1018
//返回值:LCD ID:0,非法;其他值,ID;
u16 LTDC_PanelID_Read(XGpio * axi_gpio_inst,unsigned chanel)
{
u32 idx=0;
idx = XGpio_DiscreteRead(axi_gpio_inst,chanel); //读取按键数据
switch(idx)
{
case 0:return 0x4342; //4.3寸屏,480*272分辨率
case 1:return 0x7084; //7寸屏,800*480分辨率
case 2:return 0x7016; //7寸屏,1024*600分辨率
case 4:return 0x4384; //4.3寸屏,800*480分辨率
case 5:return 0x1018; //10.1寸屏,1280*800分辨率
default:return 0;
}
}
*/display_ctrl.h
#ifndef DISPLAY_CTRL_H_
#define DISPLAY_CTRL_H_
/* ------------------------------------------------------------ */
/* Include File Definitions */
/* ------------------------------------------------------------ */
#include "xil_types.h"
#include "xvtc.h"
#include "lcd_modes.h"
//#include "xgpio.h"
/* ------------------------------------------------------------ */
/* Miscellaneous Declarations */
/* ------------------------------------------------------------ */
#define BIT_DISPLAY_RED 16
#define BIT_DISPLAY_GREEN 8
#define BIT_DISPLAY_BLUE 0
/*
* This driver currently supports frames.
*/
#define DISPLAY_NUM_FRAMES 1
/* ------------------------------------------------------------ */
/* General Type Declarations */
/* ------------------------------------------------------------ */
typedef enum {
DISPLAY_STOPPED = 0,
DISPLAY_RUNNING = 1
} DisplayState;
typedef struct {
XVtc vtc; /*VTC driver struct*/
VideoMode vMode; /*Current Video mode*/
double pxlFreq; /* Frequency of clock currently being generated */
DisplayState state; /* Indicates if the Display is currently running */
} DisplayCtrl;
/* ------------------------------------------------------------ */
/* Procedure Declarations */
/* ------------------------------------------------------------ */
int DisplayStop(DisplayCtrl *dispPtr);
int DisplayStart(DisplayCtrl *dispPtr);
int DisplayInitialize(DisplayCtrl *dispPtr,u16 vtcId);
int DisplaySetMode(DisplayCtrl *dispPtr, const VideoMode *newMode);
int DisplayChangeFrame(DisplayCtrl *dispPtr, u32 frameIndex);
//u16 LTDC_PanelID_Read(XGpio * axi_gpio_inst, unsigned chanel);
/* ------------------------------------------------------------ */
/************************************************************************/
#endif /* DISPLAY_CTRL_H_ */lcd_modes.h
#ifndef LCD_MODES_H_
#define LCD_MODES_H_
typedef struct {
char label[64]; /* Label describing the resolution */
u32 width; /*Width of the active video frame*/
u32 height; /*Height of the active video frame*/
u32 hps; /*Start time of Horizontal sync pulse, in pixel clocks (active width + H. front porch)*/
u32 hpe; /*End time of Horizontal sync pulse, in pixel clocks (active width + H. front porch + H. sync width)*/
u32 hmax; /*Total number of pixel clocks per line (active width + H. front porch + H. sync width + H. back porch) */
u32 hpol; /*hsync pulse polarity*/
u32 vps; /*Start time of Vertical sync pulse, in lines (active height + V. front porch)*/
u32 vpe; /*End time of Vertical sync pulse, in lines (active height + V. front porch + V. sync width)*/
u32 vmax; /*Total number of lines per frame (active height + V. front porch + V. sync width + V. back porch) */
u32 vpol; /*vsync pulse polarity*/
double freq; /*Pixel Clock frequency*/
} VideoMode;
static const VideoMode VMODE_480x272 = {
.label = "480x272@60Hz",
.width = 480,
.height = 272,
.hps = 482,
.hpe = 523,
.hmax = 525,
.hpol = 0,
.vps = 274,
.vpe = 284,
.vmax = 286,
.vpol = 0,
.freq = 9
};
static const VideoMode VMODE_640x480 = {
.label = "640x480@60Hz",
.width = 640,
.height = 480,
.hps = 656,
.hpe = 752,
.hmax = 799,
.hpol = 0,
.vps = 490,
.vpe = 492,
.vmax = 524,
.vpol = 0,
.freq = 25.12
};
static const VideoMode VMODE_800x480 = {
.label = "800x480@60Hz",
.width = 800,
.height= 480,
.hps = 840,
.hpe = 968,
.hmax = 1056,
.hpol = 0,
.vps = 490,
.vpe = 492,
.vmax = 525,
.vpol = 0,
.freq = 33.0
};
static const VideoMode VMODE_800x600 = {
.label = "800x600@60Hz",
.width = 800,
.height = 600,
.hps = 840,
.hpe = 968,
.hmax = 1055,
.hpol = 1,
.vps = 601,
.vpe = 605,
.vmax = 627,
.vpol = 1,
.freq = 40.0
};
static const VideoMode VMODE_1024x600 = {
.label = "1024x600@60Hz",
.width = 1024,
.height = 600,
.hps = 1164,
.hpe = 1184,
.hmax = 1344,
.hpol = 0,
.vps = 620,
.vpe = 623,
.vmax = 635,
.vpol = 0,
.freq = 50.0
};
static const VideoMode VMODE_1280x800 = {
.label = "1280x800@60Hz",
.width = 1280,
.height = 800,
.hps = 1360,
.hpe = 1370,
.hmax = 1440,
.hpol = 0,
.vps = 810,
.vpe = 813,
.vmax = 823,
.vpol = 0,
.freq = 70.0
};
static const VideoMode VMODE_1280x1024 = {
.label = "1280x1024@60Hz",
.width = 1280,
.height = 1024,
.hps = 1328,
.hpe = 1440,
.hmax = 1687,
.hpol = 1,
.vps = 1025,
.vpe = 1028,
.vmax = 1065,
.vpol = 1,
.freq = 108.0
};
static const VideoMode VMODE_1280x720 = {
.label = "1280x720@60Hz",
.width = 1280,
.height = 720,
.hps = 1390,
.hpe = 1430,
.hmax = 1649,
.hpol = 1,
.vps = 725,
.vpe = 730,
.vmax = 749,
.vpol = 1,
.freq = 74.25, //74.2424 is close enough
};
static const VideoMode VMODE_1920x1080 = {
.label = "1920x1080@60Hz",
.width = 1920,
.height = 1080,
.hps = 2008,
.hpe = 2052,
.hmax = 2199,
.hpol = 1,
.vps = 1084,
.vpe = 1089,
.vmax = 1124,
.vpol = 1,
.freq = 148.5 //148.57 is close enough
};
#endif /* LCD_MODES_H_ */
（3）main.c
#include "stdio.h"
#include "xil_printf.h"
#include "xparameters.h"
#include "xil_cache.h"
#include "xaxivdma.h"
#include "vdma_api/vdma_api.h"
#include "display_ctrl/display_ctrl.h"
#include "xclk_wiz.h"
#include "clk_wiz/clk_wiz.h"
#include "sleep.h"
//======================宏定义======================//
#define VDMA_ID XPAR_AXIVDMA_0_DEVICE_ID //VDMA器件ID
#define VTC_ID XPAR_VTC_0_DEVICE_ID //VTC器件ID
#define CLK_WIZ_ID XPAR_CLK_WIZ_0_DEVICE_ID //时钟IP核器件ID
#define DDR_BASE_ADDR XPAR_PS7_DDR_0_S_AXI_BASEADDR //DDR的基地址（在xparameters.h或lscript.ld查看）
#define MEM_BASE_ADDR (DDR_BASE_ADDR + 0x01000000) //DDR中存储数据缓存的基地址（确保在堆栈已使用DDR范围之后，lscript.ld查看）
#define PIXEL_BYTE 3 //一个像素数据所占字节（RGB888 3字节）
//==================函数、变量声明==================//
XClk_Wiz CLK_WIZ; //时钟IP核实例
XAxiVdma Vdma; //VDMA实例
VideoMode vd_mode; //lcd_modes.h中定义的结构体，包含视频分辨率格式的各个参数
DisplayCtrl dispCtrl; //display_ctrl.h中定义的结构体，包含视频分辨率格式的各个参数
static void Set_Mode(int mode);//调整输出分辨率
static void Write_Colorbar(); //向DDR数据缓存区域写数据
//======================主函数======================//
int main()
{
xil_printf("VDMA VGA Colorbar Test\r\n");
for (int i=1; i<=3; i++)
{
//调整输出分辨率
Set_Mode(i);
//配置时钟IP输出频率（单位MHz）
clk_wiz_cfg(CLK_WIZ_ID, vd_mode.freq);
xil_printf("%u,%u",vd_mode.width,vd_mode.height);
//配置并启动VDMA:（本例未使用中断）
//(VDMA实例指针，器件ID，图像宽度，图像高度，帧缓存起始地址，中断帧计数(传输多少帧产生中断)，中断使能，读写模式)
run_vdma_frame_buffer(&Vdma, VDMA_ID, vd_mode.width, vd_mode.height, (int)MEM_BASE_ADDR, 0, 0, ONLY_READ);
//初始化dispCtrl结构体(vd_mode默认1280x720@60)、初始化VTC
DisplayInitialize(&dispCtrl, VTC_ID);
//设置VTC时序参数
DisplaySetMode(&dispCtrl, &vd_mode);
//启动VTC时序生成
DisplayStart(&dispCtrl);
//向DDR数据缓存区域写数据（写彩条图像）
Write_Colorbar((u8*)MEM_BASE_ADDR , vd_mode.width, vd_mode.height);
sleep(5); //每隔5s切换一次分辨率
}
return 0;
}
//=============向DDR数据缓存区域写数据==============//
/*
* IMG_Buffer 指针，指向图像缓存的起始地址
* IMG_WIDTH 图像宽度
* IMG_HIGHT 图像高度
*/
void Write_Colorbar(u8 *IMG_Buffer, u32 IMG_WIDTH, u32 IMG_HIGHT)
{
u8 RGB_r, RGB_g, RGB_b;
int x, y, addr;
int segment_width = IMG_WIDTH / 7; // 每种颜色占1/7宽度
// 向DDR缓存区域写像素数据（RGB888）
for(y = 0; y < IMG_HIGHT; y++) {
for(x = 0; x < IMG_WIDTH; x++) {
// 根据x坐标确定颜色
if(x < segment_width * 1) { // 红色
RGB_r = 0xFF; RGB_g = 0x00; RGB_b = 0x00;
}
else if(x < segment_width * 2) { // 橙色
RGB_r = 0xFF; RGB_g = 0x4F; RGB_b = 0x00;
}
else if(x < segment_width * 3) { // 黄色
RGB_r = 0xFF; RGB_g = 0xBF; RGB_b = 0x00;
}
else if(x < segment_width * 4) { // 绿色
RGB_r = 0x00; RGB_g = 0xFF; RGB_b = 0x00;
}
else if(x < segment_width * 5) { // 青色
RGB_r = 0x00; RGB_g = 0xFF; RGB_b = 0xFF;
}
else if(x < segment_width * 6) { // 蓝色
RGB_r = 0x00; RGB_g = 0x00; RGB_b = 0xFF;
}
else { // 紫色
RGB_r = 0x7F; RGB_g = 0x00; RGB_b = 0xFF;
}
addr = y * (IMG_WIDTH * PIXEL_BYTE) + x * PIXEL_BYTE;
IMG_Buffer[addr + 0] = RGB_b; // B
IMG_Buffer[addr + 1] = RGB_g; // G
IMG_Buffer[addr + 2] = RGB_r; // R
}
}
// 刷新Cache，数据更新至内存
Xil_DCacheFlush();
xil_printf("Colorbar data ready\r\n");
}
//==================调整输出分辨率==================//
void Set_Mode(int mode)
{
switch(mode){
case 1 : vd_mode = VMODE_640x480; break;
case 2 : vd_mode = VMODE_800x600; break;
case 3 : vd_mode = VMODE_1280x720; break;
default : vd_mode = VMODE_1280x720; break;
}
}
四、效果
下载后，间隔 5s 依次切换 640*480@60Hz、800x600@60Hz、1280*720@60Hz 三种分辨率进行彩条显示（gif 图片压缩后导致看起来有杂点很有点糊，实际显示器上面很清晰）
