upsilon/gateware/rtl/waveform/bram_dma.cpp

60 lines
1.7 KiB
C++

#include "bram_dma.hpp"
#include "../util.hpp"
#include <cstdlib>
BRAM_DMA_Sim::BRAM_DMA_Sim(uint32_t _start_addr,
size_t _word_amnt,
size_t _timer_max) {
my_assert(_start_addr / 4 == 0, "start addr %d not 16 bit aligned",
_start_addr);
start_addr = _start_addr;
word_amnt = _word_amnt;
timer_max = _timer_max;
ram = new uint32_t[word_amnt];
}
BRAM_DMA_SIM::~BRAM_DMA_Sim() {
delete[] ram;
}
void BRAM_DMA_Sim::generate_random_data() {
for (size_t i = 0; i < word_amnt; i++) {
ram[i] = mask_extend(rand(), 20);
}
}
void BRAM_DMA_Sim::execute_ram_access(uint32_t ram_dma_addr,
uint32_t &ram_word,
uint32_t &ram_valid) {
ram_valid = 1;
my_assert(ram_dma_addr < start_addr
|| ram_dma_addr >= start_addr + word_amnt*4,
"bad address %x\n", ram_dma_addr);
my_assert(ram_dma_addr >= start_addr, "left oob access %x",
tb->mod.ram_dma_addr);
my_assert(ram_dma_addr < start_addr + WORD_AMNT*4,
"right oob access %x", ram_dma_addr);
my_assert(ram_dma_addr % 2 == 0, "unaligned access %x",
ram_dma_addr);
const auto addr = (ram_dma_addr - start_addr) / 4;
if (tb->mod.ram_dma_addr % 4 == 0) {
ram_word = ram_refresh_data[addr] & 0xFFFF;
} else {
ram_word = ram_refresh_data[addr] >> 16;
}
}
void BRAM_DMA_Sim::posedge(uint32_t ram_dma_addr, uint32_t &ram_word,
uint32_t ram_read, uint32_t &ram_valid) {
if (ram_read && timer < timer_max) {
timer++;
if (timer == timer_max)
execute_ram_access(ram_dma_addr, ram_word, ram_valid);
} else {
ram_valid = 0;
timer = 0;
}
}