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|
`include "gfx/gfx_defs.sv"
module gfx_rop
(
input logic clk,
rst_n,
input vram_addr frag_base,
input frag_paint in,
input logic in_valid,
output logic in_ready,
input logic rop_waitrequest,
output logic rop_write,
output vram_word rop_writedata,
output vram_addr rop_address,
output linear_coord mask_addr,
output logic mask_assert
);
enum int unsigned
{
IDLE,
WRITE_LO,
WRITE_HI
} state;
logic hi;
vram_word color_hi, color_lo;
frag_paint hold;
assign {color_hi, color_lo} = hold.color;
assign mask_addr = hold.addr;
assign rop_address = frag_base + {5'd0, hold.addr, hi};
assign rop_writedata = hi ? color_hi : color_lo;
always_comb begin
hi = 1'bx;
in_ready = 0;
rop_write = 0;
mask_assert = 0;
unique case (state)
IDLE:
in_ready = 1;
WRITE_LO: begin
hi = 0;
rop_write = 1;
mask_assert = 1;
end
WRITE_HI: begin
hi = 1;
in_ready = !rop_waitrequest;
rop_write = 1;
end
endcase
end
always_ff @(posedge clk or negedge rst_n)
if (!rst_n)
state <= IDLE;
else unique case (state)
IDLE:
if (in_valid)
state <= WRITE_LO;
WRITE_LO:
if (!rop_waitrequest)
state <= WRITE_HI;
WRITE_HI:
if (!rop_waitrequest)
state <= in_valid ? WRITE_LO : IDLE;
endcase
always_ff @(posedge clk)
if (in_ready)
hold <= in;
endmodule
|
