RndMnkIII
commented
3 months ago Hi, the Y/C module in Analogizer is include as standalone, not integrated in the MiSTer framework full pipeline, When instantiating it, it needs to be provided with the following parameters whose value is calculated based on the pixel clock frequency used by the core. For example for the Irem M92 core: using a base clock frequency of 40MHz needs the following parameter values, this core can work either in NTSC or PAL modes using Y/C video output:
wire [39:0] CHROMA_PHASE_INC; wire [26:0] COLORBURST_RANGE; wire [4:0] CHROMA_ADD; wire [4:0] CHROMA_MULT; wire YC_EN; wire PALFLAG;
parameter NTSC_REF = 3.579545;
parameter PAL_REF = 4.43361875;
// Colorburst Lenth Calculation to send to Y/C Module, based on the CLK_VIDEO of the core
localparam [6:0] COLORBURST_START = (3.7 (CLK_VIDEO_NTSC/NTSC_REF));
localparam [9:0] COLORBURST_NTSC_END = (9 (CLK_VIDEO_NTSC/NTSC_REF)) + COLORBURST_START;
localparam [9:0] COLORBURST_PAL_END = (10 * (CLK_VIDEO_PAL/PAL_REF)) + COLORBURST_START;
// Parameters to be modifed
parameter CLK_VIDEO_NTSC = 40.000000; // Must be filled E.g XX.X Hz - CLK_VIDEO
parameter CLK_VIDEO_PAL = 40.000000; // Must be filled E.g XX.X Hz - CLK_VIDEO
localparam [39:0] NTSC_PHASE_INC = 40'd98393783741; // ((NTSC_REF**2^40) / CLK_VIDEO_NTSC)
localparam [39:0] PAL_PHASE_INC = 40'd121870384219; // ((PAL_REF*2^40) / CLK_VIDEO_PAL)
// Send Parameters to Y/C Module
assign CHROMA_PHASE_INC = (analogizer_video_type == 4'h4) || (analogizer_video_type == 4'hC) ? PAL_PHASE_INC : NTSC_PHASE_INC;
assign PALFLAG = (analogizer_video_type == 4'h4) || (analogizer_video_type == 4'hC);
assign CHROMA_ADD = 5'd0; //yc_chroma_add_s;
assign CHROMA_MULT = 5'd0; //yc_chroma_mult_s;
assign COLORBURST_RANGE = {COLORBURST_START, COLORBURST_NTSC_END, COLORBURST_PAL_END}; // Pass colorburst length
rp-jt
jotego
real-amano
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