add basic verilator sim

This commit is contained in:
saji 2024-05-19 00:15:53 -05:00
parent b248c4d731
commit d4df01f5c6
5 changed files with 309 additions and 104 deletions

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@ -58,6 +58,9 @@
# loader
openfpgaloader
ecpdap # easier to poke probes.
# for building the simulator
cmake
];
};
});

2
sim/.gitignore vendored Normal file
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@ -0,0 +1,2 @@
build/
.cache/

36
sim/CMakeLists.txt Normal file
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@ -0,0 +1,36 @@
cmake_minimum_required(VERSION 3.20)
include(FetchContent)
project(groovylight-sim)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_C_STANDARD 11)
FetchContent_Declare(
dear_imgui
GIT_REPOSITORY https://github.com/ocornut/imgui.git
GIT_TAG 231cbee0fc4f59dbe5b8b853a11b08dc84e57c65 # version 1.90.5
)
FetchContent_Declare(
sokol
GIT_REPOSITORY https://github.com/floooh/sokol.git
GIT_TAG 55bc9cf3fa4051d485d10412c75c893c3135e885
)
FetchContent_MakeAvailable(sokol dear_imgui)
set(CMAKE_EXPORT_COMPILE_COMMANDS TRUE)
find_package(verilator HINTS $ENV{VERILATOR_ROOT})
add_executable(sim)
target_sources(sim PRIVATE
src/main.cpp
)
list(APPEND VSOURCES ../verilog/hub75e.sv ../verilog/lineram.v)
verilate(sim SOURCES ${VSOURCES} TRACE VERILATOR_ARGS -Wno-MULTITOP)

160
sim/src/main.cpp Normal file
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@ -0,0 +1,160 @@
#include "Vhub75e.h"
#include "verilated.h"
#include "verilated_vcd_c.h"
#include <array>
#include <cstdint>
#include <memory>
#include <queue>
#include <stdio.h>
#include <vector>
// slices the RGB values for us.
uint8_t rgb_slice(uint32_t rgb, uint8_t bit) {
if (bit > 8) {
// todo: panic
return 0;
}
uint8_t r = (rgb >> (16 + bit)) & 1;
uint8_t g = (rgb >> (8 + bit)) & 1;
uint8_t b = (rgb >> bit) & 1;
return (r << 2) & (g << 1) & (b << 1);
}
class HUB75Reciever {
typedef std::vector<unsigned char> row_array;
int xsize;
int ysize;
row_array row_upper;
row_array row_lower;
// the previous row values that were latched in.
std::vector<row_array> past_rows;
// the pulse width for each output, in clock cycles.
std::vector<int> pulse_widths;
int bit_position = 7; // the bit that is currently being shifted in
int output_period_cnt;
// if oe = 0, count clocks. when oe = 1, store value into
// pulse_widths[display_bit];
// previous latch value, used to identify when to latch.
unsigned char prev_latch = 0;
// previous display clock value, used to detect rising edge.
unsigned char prev_display_clk = 0;
unsigned char prev_oe = 0;
public:
HUB75Reciever(int xsize, int ysize) : row_upper(xsize, 0) {
this->xsize = xsize;
this->ysize = ysize;
};
// evaluates the reciever.
void eval(const int oe, const int latch, const int display_clk,
const int rgb0) {
if (prev_display_clk == 0 && display_clk == 1) {
// display clock rising edge.
row_upper.push_back(rgb0);
}
if (prev_latch == 0 && latch == 1) {
// latch in the data: reverse the rows, and pu
std::reverse(row_upper.begin(), row_upper.end());
past_rows.push_back(row_upper);
row_upper.clear();
}
if (oe == 0) {
if (prev_oe == 1) {
// falling edge.
output_period_cnt = 0;
} else {
output_period_cnt++;
}
} else {
// rising edge: store the output
}
// update previous values
prev_display_clk = display_clk;
prev_latch = latch;
prev_oe = oe;
}
};
class FakeBRAM {
std::array<uint64_t, 512> ram{};
std::queue<uint16_t> addr_lookup_q;
public:
FakeBRAM(int latency) : addr_lookup_q() {
for (int i = 0; i < latency; i++) {
addr_lookup_q.push(0);
}
for (int i = 0; i < ram.size(); i++) {
ram[i] = i;
}
};
uint64_t tick(int addr) {
// we push and pop in the same tick: this way we keep the queue the same
// size, acting as a pipeline delay.
addr_lookup_q.push(addr);
auto addr_to_load = addr_lookup_q.front();
addr_lookup_q.pop();
return ram.at(addr_to_load);
}
// TODO: allow accessing/setting the data
};
void LineDriverTest(VerilatedContext &ctx) {
// create the hub75e driver and run some basic tests
// we generate 512 random color values (24 bits)
// we load them in.
unsigned long counter = 0; // counts positive edges.
unsigned long simtime = 0;
auto dut = std::make_unique<Vhub75e>(&ctx, "dut");
VerilatedVcdC *m_trace = new VerilatedVcdC;
dut->trace(m_trace, 5);
auto bram = FakeBRAM(1);
printf("Performing basic test\n");
bool done = false;
m_trace->open("waveform.vcd");
while (!done) {
dut->clk ^= 1; // toggle clock
dut->eval();
if (dut->clk == 1) {
// rising edge.
counter++;
dut->pixbuf_data = bram.tick(dut->pixbuf_addr);
}
dut->write_trig = counter < 20 ? 1 : 0;
if (counter >= 250000) {
done = true;
}
m_trace->dump(simtime);
simtime++;
}
m_trace->close();
};
int main() {
auto ctx = std::make_unique<VerilatedContext>();
ctx->traceEverOn(true);
printf("hello world!\n");
LineDriverTest(*ctx);
};

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@ -1,115 +1,119 @@
module lineram (
input [35:0] din,
input [8:0] addr_w,
output wire [35:0] dout,
output reg [35:0] dout,
input [8:0] addr_r,
input write_en,
input read_clk,
input write_clk
);
// `ifdef YOSYS
// // use the ECP5 primitive.
// PDPW16KD ram (
// .DI0 (din[0]),
// .DI1 (din[1]),
// .DI2 (din[2]),
// .DI3 (din[3]),
// .DI4 (din[4]),
// .DI5 (din[5]),
// .DI6 (din[6]),
// .DI7 (din[7]),
// .DI8 (din[8]),
// .DI9 (din[9]),
// .DI10(din[10]),
// .DI11(din[11]),
// .DI12(din[12]),
// .DI13(din[13]),
// .DI14(din[14]),
// .DI15(din[15]),
// .DI16(din[16]),
// .DI17(din[17]),
// .DI18(din[18]),
// .DI19(din[19]),
// .DI20(din[20]),
// .DI21(din[21]),
// .DI22(din[22]),
// .DI23(din[23]),
// .DI24(din[24]),
// .DI25(din[25]),
// .DI26(din[26]),
// .DI27(din[27]),
// .DI28(din[28]),
// .DI29(din[29]),
// .DI30(din[30]),
// .DI31(din[31]),
// .DI32(din[32]),
// .DI33(din[33]),
// .DI34(din[34]),
// .DI35(din[35]),
// .ADW0(addr_w[0]),
// .ADW1(addr_w[1]),
// .ADW2(addr_w[2]),
// .ADW3(addr_w[3]),
// .ADW4(addr_w[4]),
// .ADW5(addr_w[5]),
// .ADW6(addr_w[6]),
// .ADW7(addr_w[7]),
// .ADW8(addr_w[8]),
// .DO0 (dout[0]),
// .DO1 (dout[1]),
// .DO2 (dout[2]),
// .DO3 (dout[3]),
// .DO4 (dout[4]),
// .DO5 (dout[5]),
// .DO6 (dout[6]),
// .DO7 (dout[7]),
// .DO8 (dout[8]),
// .DO9 (dout[9]),
// .DO10(dout[10]),
// .DO11(dout[11]),
// .DO12(dout[12]),
// .DO13(dout[13]),
// .DO14(dout[14]),
// .DO15(dout[15]),
// .DO16(dout[16]),
// .DO17(dout[17]),
// .DO18(dout[18]),
// .DO19(dout[19]),
// .DO20(dout[20]),
// .DO21(dout[21]),
// .DO22(dout[22]),
// .DO23(dout[23]),
// .DO24(dout[24]),
// .DO25(dout[25]),
// .DO26(dout[26]),
// .DO27(dout[27]),
// .DO28(dout[28]),
// .DO29(dout[29]),
// .DO30(dout[30]),
// .DO31(dout[31]),
// .DO32(dout[32]),
// .DO33(dout[33]),
// .DO34(dout[34]),
// .DO35(dout[35]),
// .ADR0(addr_r[0]),
// .ADR1(addr_r[1]),
// .ADR2(addr_r[2]),
// .ADR3(addr_r[3]),
// .ADR4(addr_r[4]),
// .ADR5(addr_r[5]),
// .ADR6(addr_r[6]),
// .ADR7(addr_r[7]),
// .ADR8(addr_r[8]),
// .CER(1),
// .CEW(1),
// .CLKR(read_clk),
// .CLKW(write_clk),
//
//
// );
// `else
reg [35:0] ram [2**9];
`ifdef YOSYS
// use the ECP5 primitive.
PDPW16KD #(.REGMODE("OUTREG")) ram (
.DI0 (din[0]),
.DI1 (din[1]),
.DI2 (din[2]),
.DI3 (din[3]),
.DI4 (din[4]),
.DI5 (din[5]),
.DI6 (din[6]),
.DI7 (din[7]),
.DI8 (din[8]),
.DI9 (din[9]),
.DI10(din[10]),
.DI11(din[11]),
.DI12(din[12]),
.DI13(din[13]),
.DI14(din[14]),
.DI15(din[15]),
.DI16(din[16]),
.DI17(din[17]),
.DI18(din[18]),
.DI19(din[19]),
.DI20(din[20]),
.DI21(din[21]),
.DI22(din[22]),
.DI23(din[23]),
.DI24(din[24]),
.DI25(din[25]),
.DI26(din[26]),
.DI27(din[27]),
.DI28(din[28]),
.DI29(din[29]),
.DI30(din[30]),
.DI31(din[31]),
.DI32(din[32]),
.DI33(din[33]),
.DI34(din[34]),
.DI35(din[35]),
.ADW0(addr_w[0]),
.ADW1(addr_w[1]),
.ADW2(addr_w[2]),
.ADW3(addr_w[3]),
.ADW4(addr_w[4]),
.ADW5(addr_w[5]),
.ADW6(addr_w[6]),
.ADW7(addr_w[7]),
.ADW8(addr_w[8]),
.DO0 (dout[0]),
.DO1 (dout[1]),
.DO2 (dout[2]),
.DO3 (dout[3]),
.DO4 (dout[4]),
.DO5 (dout[5]),
.DO6 (dout[6]),
.DO7 (dout[7]),
.DO8 (dout[8]),
.DO9 (dout[9]),
.DO10(dout[10]),
.DO11(dout[11]),
.DO12(dout[12]),
.DO13(dout[13]),
.DO14(dout[14]),
.DO15(dout[15]),
.DO16(dout[16]),
.DO17(dout[17]),
.DO18(dout[18]),
.DO19(dout[19]),
.DO20(dout[20]),
.DO21(dout[21]),
.DO22(dout[22]),
.DO23(dout[23]),
.DO24(dout[24]),
.DO25(dout[25]),
.DO26(dout[26]),
.DO27(dout[27]),
.DO28(dout[28]),
.DO29(dout[29]),
.DO30(dout[30]),
.DO31(dout[31]),
.DO32(dout[32]),
.DO33(dout[33]),
.DO34(dout[34]),
.DO35(dout[35]),
.ADR0(addr_r[0]),
.ADR1(addr_r[1]),
.ADR2(addr_r[2]),
.ADR3(addr_r[3]),
.ADR4(addr_r[4]),
.ADR5(addr_r[5]),
.ADR6(addr_r[6]),
.ADR7(addr_r[7]),
.ADR8(addr_r[8]),
.CER(1),
.CEW(1),
.CLKR(read_clk),
.CLKW(write_clk),
.CSW1(0),
.CSW2(0),
.CSW3(0),
.CSR1(0),
.CSR2(0),
.CSR3(0),
);
`else
reg [35:0] ram [2**9]/*verilator public*/;
`ifndef YOSYS
initial begin
@ -125,5 +129,5 @@ module lineram (
always @(posedge read_clk) begin
dout <= ram[addr_r];
end
// `endif
`endif
endmodule