blob: 2c4581e44fe503e74058b5fcd8eea85bf40261b3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
module gfx_bootrom
import gfx::*;
(
input logic clk,
rst_n,
gfx_axil.s axis
);
localparam ROM_WORDS_LOG = 8;
enum int unsigned
{
WAIT,
READ,
RDATA,
READY
} state;
word read, rom[1 << ROM_WORDS_LOG];
logic[ROM_WORDS_LOG - 1:0] read_addr;
assign axis.bvalid = 0;
assign axis.wready = 0;
assign axis.awready = 0;
always_ff @(posedge clk or negedge rst_n)
if (~rst_n) begin
state <= WAIT;
axis.rvalid <= 0;
axis.arready <= 0;
end else begin
axis.arready <= 0;
unique case (state)
WAIT:
if (axis.arvalid & ~axis.arready)
state <= READ;
READ:
state <= RDATA;
RDATA: begin
state <= READY;
axis.rvalid <= 1;
end
READY:
if (axis.rready) begin
state <= WAIT;
axis.rvalid <= 0;
axis.arready <= 1;
end
endcase
end
always_ff @(posedge clk) begin
read <= rom[read_addr];
read_addr <= axis.araddr[$bits(read_addr) + SUBWORD_BITS - 1:SUBWORD_BITS];
axis.rdata <= read;
end
initial
$readmemh("gfx_bootrom.hex", rom);
endmodule
|
