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Valued Contributor III
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Camera to FIFO SD-RAM and then VGA display

I am trying to connect a linescan grayscale video camera to a DE2-115 board using CameraLink base mode and the CLR-HSMC receiver card. My aim is to buffer a few lines and display the info as a 2-D image on a VGA monitor. The camera outputs 1024 8-bit pixels per line and it has a line rate of 5kHz, which means a pixel rate of 5.1 MHz approximately. 

 

I am facing two major problems with my task and I need your help desperately.  

 

1. To capture the data after the CameraLink deserialization, I wrote the following code. 

 

module LineScan_Capture ( iRST_n, iCLK, iDATA, iLVAL, iDVAL, oDATA ); input iRST_n; input iCLK; //clock of camera input iDATA; input iLVAL; input iDVAL; output oDATA; reg line_ccd_data; always@(posedge iCLK or negedge iRST_n) begin if(!iRST_n) line_ccd_data <= 0; else if ({iLVAL,iDVAL}==2'b11) line_ccd_data <= iDATA; end assign oDATA = line_ccd_data; endmodule I think this code is doing the job by outputting the valid data. Now I want to make a '2-D frame' out of these data by joining up say 80 lines of data, and then send this to a dual FIFO SD-RAM to be used for VGA display. But how do I count the lines? I thought about making a counter that increments every time the LVAL goes from 0 to 1, but I don't know how to do that. I also thought about simply counting to 81920 (i.e. 1024 pixels x 80 lines) every time the {iLVAL,iDVAL} condition is satisfied but I am not sure if this is the correct way to do it. Any advice please? 

 

2. Now to display this on a 640x480 VGA screen, there is a demo file that came with the CLR-HSMC card and which assumes we are using a 10-bit color 2-D camera . I am not putting all the code here but just section instantiations of modules Sdram_Control and VGA_Controller. (see attachment for the Sdram_control files) 

 

Sdram_Control u7( //HOST Side .RESET_N(KEY), .CLK(sdram_ctrl_clk), //FIFO Write Side 1 .WR1_DATA({1'b0,green,blue}), // 16-bit width of data bus in/out SDRAM Controller .WR1(dval), // Write Request .WR1_ADDR(0), .WR1_MAX_ADDR(640*480/2), .WR1_LENGTH(8'h50), //?? .WR1_LOAD(!rst_n), .WR1_CLK(CLR_BASE_CLK), //FIFO Write Side 2 .WR2_DATA({1'b0,green,red}), .WR2(dval), .WR2_ADDR(23'h100000), .WR2_MAX_ADDR(23'h100000+640*480/2), .WR2_LENGTH(8'h50), .WR2_LOAD(!rst_n), .WR2_CLK(CLR_BASE_CLK), //FIFO Read Side 1 .RD1_DATA(Read_DATA1), .RD1(Read), .RD1_ADDR(0), .RD1_MAX_ADDR(640*480/2), .RD1_LENGTH(8'h50), .RD1_LOAD(!rst_n), .RD1_CLK(~VGA_CTRL_CLK), //FIFO Read Side 2 .RD2_DATA(Read_DATA2), . . //SDRAM Side ); VGA_Controller u1( //Host Side .oRequest(Read), .iRed(Read_DATA2), .iGreen({Read_DATA1,Read_DATA2}), .iBlue(Read_DATA1), //VGA Side . . //Control Signal . . ); I don't fully understand this code.  

- What is WR1_LENGTH, and how do they choose this value of 8'h50? 

- In WR1(dval) for my case, dval is the condition that will be high every time I count 80 lines in the previous code right?  

- My data is 8-bit only. If I assign oDATA from the previous code to three 8-bit wires red, green and blue, can I do this on the FIFO side: 

 

.WR1_DATA({4'b0000,green[7:4],blue[7:0]})  

.WR2_DATA({4'b0000,green[3:0],red[7:0]}) 

 

and then on the VGA side  

 

.iRed(Read_DATA2[7:0]), 

.iGreen({Read_DATA1[11:8],Read_DATA2[11:8]}), 

.iBlue(Read_DATA1[7:0]), 

 

 

I know it is a lot to ask, but I have been stuck on this for too long and I would be extremely grateful for any help.
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Valued Contributor III
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hello please did u find an answer for this question  

What is WR1_LENGTH, and how do they choose this value of 8'h50? 

thanks
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