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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/*
* ECP5 PicoRV32 demo
*
* Copyright (C) 2017 Clifford Wolf <clifford@clifford.at>
* Copyright (C) 2018 David Shah <dave@ds0.me>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
`ifdef PICORV32_V
`error "attosoc.v must be read before picorv32.v!"
`endif
`define PICORV32_REGS picosoc_regs
module attosoc (
input clk,
output reg [7:0] led
);
reg [5:0] reset_cnt = 0;
wire resetn = &reset_cnt;
always @(posedge clk) begin
reset_cnt <= reset_cnt + !resetn;
end
parameter integer MEM_WORDS = 256;
parameter [31:0] STACKADDR = (4*MEM_WORDS); // end of memory
parameter [31:0] PROGADDR_RESET = 32'h 0000_0000; // ROM at 0x0
parameter integer ROM_BYTES = 256;
reg [7:0] rom [0:ROM_BYTES-1];
wire [31:0] rom_rdata = {rom[mem_addr+3], rom[mem_addr+2], rom[mem_addr+1], rom[mem_addr+0]};
initial $readmemh("firmware.hex", rom);
wire mem_valid;
wire mem_instr;
wire mem_ready;
wire [31:0] mem_addr;
wire [31:0] mem_wdata;
wire [3:0] mem_wstrb;
wire [31:0] mem_rdata;
wire rom_ready = mem_valid && mem_addr[31:24] == 8'h00;
wire iomem_valid;
wire iomem_ready;
wire [31:0] iomem_addr;
wire [31:0] iomem_wdata;
wire [3:0] iomem_wstrb;
wire [31:0] iomem_rdata;
assign iomem_valid = mem_valid && (mem_addr[31:24] > 8'h 01);
assign iomem_ready = 1'b1;
assign iomem_wstrb = mem_wstrb;
assign iomem_addr = mem_addr;
assign iomem_wdata = mem_wdata;
wire [31:0] spimemio_cfgreg_do;
always @(posedge clk)
if (iomem_valid && iomem_wstrb[0])
led <= iomem_wdata[7:0];
assign mem_ready = (iomem_valid && iomem_ready) || rom_ready;
assign mem_rdata = rom_rdata;
picorv32 #(
.STACKADDR(STACKADDR),
.PROGADDR_RESET(PROGADDR_RESET),
.PROGADDR_IRQ(32'h 0000_0000),
.BARREL_SHIFTER(0),
.COMPRESSED_ISA(0),
.ENABLE_MUL(0),
.ENABLE_DIV(0),
.ENABLE_IRQ(0),
.ENABLE_IRQ_QREGS(0)
) cpu (
.clk (clk ),
.resetn (resetn ),
.mem_valid (mem_valid ),
.mem_instr (mem_instr ),
.mem_ready (mem_ready ),
.mem_addr (mem_addr ),
.mem_wdata (mem_wdata ),
.mem_wstrb (mem_wstrb ),
.mem_rdata (mem_rdata )
);
endmodule
// Implementation note:
// Replace the following two modules with wrappers for your SRAM cells.
module picosoc_regs (
input clk, wen,
input [5:0] waddr,
input [5:0] raddr1,
input [5:0] raddr2,
input [31:0] wdata,
output [31:0] rdata1,
output [31:0] rdata2
);
reg [31:0] regs [0:31];
always @(posedge clk)
if (wen) regs[waddr[4:0]] <= wdata;
assign rdata1 = regs[raddr1[4:0]];
assign rdata2 = regs[raddr2[4:0]];
endmodule
|
