Altera University Program IP Core中有很多很受用的IP核，本人对其中的VGA核很感兴趣，却发现其并不是直接可用的（也许是我没找到），于是便写了个接口挂到了NiosII上。由于原例中在DE2开发板上实现，但其显存不能满足我的要求，于是又稍微改动使其能在DE2-70上实现。
Codemodule vgaip_inst (
// inputs:
avs_s1_address,
avs_s1_byteenable,
avs_s1_chipselect,
avs_s1_read,
avs_s1_write,
avs_s1_writedata,
csi_clockreset_clk,
csi_clockreset_reset,
// outputs:
avs_s1_export_SRAM_ADDR,
avs_s1_export_SRAM_CE_N,
avs_s1_export_SRAM_DQ,
avs_s1_export_SRAM_LB_N,
avs_s1_export_SRAM_OE_N,
avs_s1_export_SRAM_UB_N,
avs_s1_export_SRAM_WE_N,
avs_s1_export_VGA_B,
avs_s1_export_VGA_BLANK,
avs_s1_export_VGA_G,
avs_s1_export_VGA_HS,
avs_s1_export_VGA_R,
avs_s1_export_VGA_SYNC,
avs_s1_export_VGA_VS,
avs_s1_readdata
)
;
output [ 17: 0] avs_s1_export_SRAM_ADDR;
output avs_s1_export_SRAM_CE_N;
inout [ 15: 0] avs_s1_export_SRAM_DQ;
output avs_s1_export_SRAM_LB_N;
output avs_s1_export_SRAM_OE_N;
output avs_s1_export_SRAM_UB_N;
output avs_s1_export_SRAM_WE_N;
output [ 9: 0] avs_s1_export_VGA_B;
output avs_s1_export_VGA_BLANK;
output [ 9: 0] avs_s1_export_VGA_G;
output avs_s1_export_VGA_HS;
output [ 9: 0] avs_s1_export_VGA_R;
output avs_s1_export_VGA_SYNC;
output avs_s1_export_VGA_VS;
output [ 15: 0] avs_s1_readdata;
input [ 17: 0] avs_s1_address;
input [ 1: 0] avs_s1_byteenable;
input avs_s1_chipselect;
input avs_s1_read;
input avs_s1_write;
input [ 15: 0] avs_s1_writedata;
input csi_clockreset_clk;
input csi_clockreset_reset;
wire [ 17: 0] avs_s1_export_SRAM_ADDR;
wire avs_s1_export_SRAM_CE_N;
wire [ 15: 0] avs_s1_export_SRAM_DQ;
wire avs_s1_export_SRAM_LB_N;
wire avs_s1_export_SRAM_OE_N;
wire avs_s1_export_SRAM_UB_N;
wire avs_s1_export_SRAM_WE_N;
wire [ 9: 0] avs_s1_export_VGA_B;
wire avs_s1_export_VGA_BLANK;
wire [ 9: 0] avs_s1_export_VGA_G;
wire avs_s1_export_VGA_HS;
wire [ 9: 0] avs_s1_export_VGA_R;
wire avs_s1_export_VGA_SYNC;
wire avs_s1_export_VGA_VS;
wire [ 15: 0] avs_s1_readdata;
vgaip the_vgaip
(
.avs_s1_address (avs_s1_address),
.avs_s1_byteenable (avs_s1_byteenable),
.avs_s1_chipselect (avs_s1_chipselect),
.avs_s1_export_SRAM_ADDR (avs_s1_export_SRAM_ADDR),
.avs_s1_export_SRAM_CE_N (avs_s1_export_SRAM_CE_N),
.avs_s1_export_SRAM_DQ (avs_s1_export_SRAM_DQ),
.avs_s1_export_SRAM_LB_N (avs_s1_export_SRAM_LB_N),
.avs_s1_export_SRAM_OE_N (avs_s1_export_SRAM_OE_N),
.avs_s1_export_SRAM_UB_N (avs_s1_export_SRAM_UB_N),
.avs_s1_export_SRAM_WE_N (avs_s1_export_SRAM_WE_N),
.avs_s1_export_VGA_B (avs_s1_export_VGA_B),
.avs_s1_export_VGA_BLANK (avs_s1_export_VGA_BLANK),
.avs_s1_export_VGA_G (avs_s1_export_VGA_G),
.avs_s1_export_VGA_HS (avs_s1_export_VGA_HS),
.avs_s1_export_VGA_R (avs_s1_export_VGA_R),
.avs_s1_export_VGA_SYNC (avs_s1_export_VGA_SYNC),
.avs_s1_export_VGA_VS (avs_s1_export_VGA_VS),
.avs_s1_read (avs_s1_read),
.avs_s1_readdata (avs_s1_readdata),
.avs_s1_write (avs_s1_write),
.avs_s1_writedata (avs_s1_writedata),
.csi_clockreset_clk (csi_clockreset_clk),
.csi_clockreset_reset (csi_clockreset_reset)
);
endmodule
Codemodule vgaip(
//nios port
//inputs
csi_clockreset_clk,
csi_clockreset_reset,
avs_s1_address,
avs_s1_byteenable,
avs_s1_chipselect,
avs_s1_read,
avs_s1_write,
avs_s1_writedata,
//outputs
avs_s1_readdata,
//vga port
//outputs
avs_s1_export_VGA_BLANK,
avs_s1_export_VGA_SYNC,
avs_s1_export_VGA_HS,
avs_s1_export_VGA_VS,
avs_s1_export_VGA_R,
avs_s1_export_VGA_G,
avs_s1_export_VGA_B,
//sram port
avs_s1_export_SRAM_DQ, // SRAM Data bus 16 Bits
avs_s1_export_SRAM_ADDR, // SRAM Address bus 18 Bits
avs_s1_export_SRAM_LB_N, // SRAM Low-byte Data Mask
avs_s1_export_SRAM_UB_N, // SRAM High-byte Data Mask
avs_s1_export_SRAM_CE_N, // SRAM Chip chipselect
avs_s1_export_SRAM_OE_N, // SRAM Output chipselect
avs_s1_export_SRAM_WE_N // SRAM Write chipselect
);
/*****************************************************************************
* Port Declarations *
*****************************************************************************/
input csi_clockreset_clk;
input csi_clockreset_reset;
input [17:0] avs_s1_address;
input [1:0] avs_s1_byteenable;
input avs_s1_chipselect;
input avs_s1_read;
input avs_s1_write;
input [15:0] avs_s1_writedata;
//outputs
output [15:0] avs_s1_readdata;
output avs_s1_export_VGA_BLANK;
output avs_s1_export_VGA_SYNC;
output avs_s1_export_VGA_HS;
output avs_s1_export_VGA_VS;
output [9:0] avs_s1_export_VGA_R;
output [9:0] avs_s1_export_VGA_G;
output [9:0] avs_s1_export_VGA_B;
inout [15:0] avs_s1_export_SRAM_DQ; // SRAM Data bus 16 Bits
output [17:0] avs_s1_export_SRAM_ADDR; // SRAM Address bus 18 Bits
output avs_s1_export_SRAM_LB_N; // SRAM Low-byte Data Mask
output avs_s1_export_SRAM_UB_N; // SRAM High-byte Data Mask
output avs_s1_export_SRAM_CE_N; // SRAM Chip chipselect
output avs_s1_export_SRAM_OE_N; // SRAM Output chipselect
output avs_s1_export_SRAM_WE_N; // SRAM Write chipselect
/*****************************************************************************
* Internal Wires and Registers Declarations *
*****************************************************************************/
// wire avs_s1_export_VGA_BLANK;
// wire avs_s1_export_VGA_SYNC;
// wire avs_s1_export_VGA_HS;
// wire avs_s1_export_VGA_VS;
// wire [9:0] avs_s1_export_VGA_R;
// wire [9:0] avs_s1_export_VGA_G;
// wire [9:0] avs_s1_export_VGA_B;
wire ready;
wire [29:0] data;
wire startofpacket;
wire endofpacket;
wire empty;
wire valid;
wire [15:0] SRAM_DQ; // SRAM Data bus 16 Bits
wire [17:0] SRAM_ADDR; // SRAM Address bus 18 Bits
wire SRAM_LB_N; // SRAM Low-byte Data Mask
wire SRAM_UB_N; // SRAM High-byte Data Mask
wire SRAM_CE_N; // SRAM Chip chipselect
wire SRAM_OE_N; // SRAM Output chipselect
wire SRAM_WE_N; // SRAM Write chipselect
Altera_UP_Avalon_Pixel_Buffer buffer(
// Inputs
.clk(csi_clockreset_clk),
.reset(csi_clockreset_reset),
.address(avs_s1_address),
.byteenable(avs_s1_byteenable),
.chipselect(avs_s1_chipselect),
.read(avs_s1_read),
.write(avs_s1_write),
.writedata(avs_s1_writedata),
.stream_out_ready(ready),
// Bi-Directional
.SRAM_DQ(avs_s1_export_SRAM_DQ),
// Outputs
.readdata(avs_s1_readdata),
.stream_out_data(data),
.stream_out_startofpacket(startofpacket),
.stream_out_endofpacket(endofpacket),
.stream_out_empty(empty),
.stream_out_valid(valid),
.SRAM_ADDR(avs_s1_export_SRAM_ADDR),
.SRAM_LB_N(avs_s1_export_SRAM_LB_N),
.SRAM_UB_N(avs_s1_export_SRAM_UB_N),
.SRAM_CE_N(avs_s1_export_SRAM_CE_N),
.SRAM_OE_N(avs_s1_export_SRAM_OE_N),
.SRAM_WE_N(avs_s1_export_SRAM_WE_N)
);
Altera_UP_Avalon_VGA vga(
// Inputs
.clk(csi_clockreset_clk),
.reset(csi_clockreset_reset),
.pixel_data(data),
.pixel_startofpacket(startofpacket),
.pixel_endofpacket(endofpacket),
.pixel_empty(empty),
.pixel_valid(valid),
// Bidirectionals
// Outputs
.pixel_ready(ready),
.VGA_BLANK(avs_s1_export_VGA_BLANK),
.VGA_SYNC(avs_s1_export_VGA_SYNC),
.VGA_HS(avs_s1_export_VGA_HS),
.VGA_VS(avs_s1_export_VGA_VS),
.VGA_R(avs_s1_export_VGA_R),
.VGA_G(avs_s1_export_VGA_G),
.VGA_B(avs_s1_export_VGA_B)
);
endmodule
C源码：
#include <stdio.h>
#include "system.h"
#include "io.h"
#include "rgb565_640x480.h"
int main()
{
unsigned int i;
unsigned int j,k;
for(;;){
for(i=0;i<640*480;i++){
//rdata=IORD_32DIRECT(SWITCH_PIO_BASE,0);
IOWR_16DIRECT(VGAIP_INST_BASE,i,rgb565[i]);
for(j=0;j<10;j++){
for(k=0;k<10;k++){;}
}
}
}
printf("Hello from Nios II!\n");
return 0;
}
显示效果：
说明：
在DE2开发板上实现，由于DE2中的SSRAM只有512K，所以640*480*3（byte）的显存是不够的显示结果是经缩放
后的效果，具体可修改Altera_UP_Avalon_Pixel_Buffer buffer模块中的相关代码。
我把代码移植到DE2-70上后，显示的就很正常了。
Altera University Program IP Core下载地址
http://www.cnblogs.com/lunix/admin/ftp://ftp.altera.com/up/pub/University_Program_IP_Cores/80
70上的源码vga_gui