diff options
Diffstat (limited to 'rtl/gfx/gfx_setup_offsets.sv')
| -rw-r--r-- | rtl/gfx/gfx_setup_offsets.sv | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/rtl/gfx/gfx_setup_offsets.sv b/rtl/gfx/gfx_setup_offsets.sv new file mode 100644 index 0000000..3b615d5 --- /dev/null +++ b/rtl/gfx/gfx_setup_offsets.sv @@ -0,0 +1,44 @@ +`include "gfx/gfx_defs.sv" + +module gfx_setup_offsets +( + input logic clk, + + input fixed inc_x, + inc_y, + input logic stall, + + output fixed offsets[`GFX_RASTER_OFFSETS] +); + + fixed x_hold[`GFX_RASTER_SIZE], y_hold[`GFX_RASTER_SIZE], + x_multiples[`GFX_RASTER_SIZE], y_multiples[`GFX_RASTER_SIZE]; + + // Asume GFX_RASTER_BITS == 2. Los ceros deberÃan optimizarse trivialmente + assign x_multiples[0] = 0; + assign y_multiples[0] = 0; + assign x_multiples[1] = inc_x; + assign y_multiples[1] = inc_y; + assign x_multiples[2] = inc_x << 1; + assign y_multiples[2] = inc_y << 1; + assign x_multiples[3] = (inc_x << 1) + a; + assign y_multiples[3] = (inc_y << 1) + b; + + genvar i; + generate + for (i = 0; i < `GFX_RASTER_SIZE; ++i) begin: multiples + always_ff @(posedge clk) + if (!stall) begin + x_hold[i] <= x_multiples[i]; + y_hold[i] <= y_multiples[i]; + end + end + + for (i = 0; i < `GFX_RASTER_OFFSETS; ++i) begin: permutations + always_ff @(posedge clk) + if (!stall) + offsets[i] <= x_hold[i % `GFX_RASTER_SIZE] + y_hold[i / `GFX_RASTER_SIZE]; + end + endgenerate + +endmodule |