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////////////////////////////////////////////////////////////////////////////////
//
//
// Filename: qspiflashsim.cpp
//
// Project: Wishbone Controlled Quad SPI Flash Controller
//
// Purpose: This library simulates the operation of a Quad-SPI commanded
// flash, such as the S25FL032P used on the Basys-3 development
// board by Digilent.
//
// This simulator is useful for testing in a Verilator/C++
// environment, where this simulator can be used in place of
// the actual hardware.
//
// Creator: Dan Gisselquist, Ph.D.
// Gisselquist Technology, LLC
//
////////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2015,2017, Gisselquist Technology, LLC
//
// This program is free software (firmware): you can redistribute it and/or
// modify it under the terms of the GNU General Public License as published
// by the Free Software Foundation, either version 3 of the License, or (at
// your option) any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program. (It's in the $(ROOT)/doc directory. Run make with no
// target there if the PDF file isn't present.) If not, see
// <http://www.gnu.org/licenses/> for a copy.
//
// License: GPL, v3, as defined and found on www.gnu.org,
// http://www.gnu.org/licenses/gpl.html
//
//
////////////////////////////////////////////////////////////////////////////////
//
//
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <stdint.h>
#include "qspiflashsim.h"
static const unsigned DEVID = 0x0115,
DEVESD = 0x014,
MICROSECONDS = 100,
MILLISECONDS = MICROSECONDS * 1000,
SECONDS = MILLISECONDS * 1000,
tW = 50 * MICROSECONDS, // write config cycle time
tBE = 32 * SECONDS,
tDP = 10 * SECONDS,
tRES = 30 * SECONDS,
// Shall we artificially speed up this process?
tPP = 12 * MICROSECONDS,
tSE = 15 * MILLISECONDS;
// or keep it at the original speed
// tPP = 1200 * MICROSECONDS,
// tSE = 1500 * MILLISECONDS;
QSPIFLASHSIM::QSPIFLASHSIM(const int lglen, bool debug) {
m_membytes = (1<<lglen);
m_memmask = (m_membytes - 1);
m_mem = new char[m_membytes];
m_pmem = new char[256];
m_state = QSPIF_IDLE;
m_last_sck = 1;
m_write_count = 0;
m_ireg = m_oreg = 0;
m_sreg = 0x01c;
m_creg = 0x001; // Iinitial creg on delivery
m_quad_mode = false;
m_mode_byte = 0;
memset(m_mem, 0x0ff, m_membytes);
}
void QSPIFLASHSIM::load(const unsigned addr, const char *fname) {
FILE *fp;
size_t len;
int nr = 0;
if (addr >= m_membytes)
return;
// If not given, then length is from the given address until the end
// of the flash memory
len = m_membytes-addr*4;
if (NULL != (fp = fopen(fname, "r"))) {
nr = fread(&m_mem[addr], sizeof(char), len, fp);
fclose(fp);
if (nr == 0) {
fprintf(stderr, "SPI-FLASH: Could not read %s\n", fname);
perror("O/S Err:");
}
} else {
fprintf(stderr, "SPI-FLASH: Could not open %s\n", fname);
perror("O/S Err:");
}
for(unsigned i=nr; i<m_membytes; i++)
m_mem[i] = 0x0ff;
}
void QSPIFLASHSIM::load(const uint32_t offset, const char *data, const uint32_t len) {
uint32_t moff = (offset & (m_memmask));
memcpy(&m_mem[moff], data, len);
}
#define QOREG(A) m_oreg = ((m_oreg & (~0x0ff))|(A&0x0ff))
int QSPIFLASHSIM::operator()(const int csn, const int sck, const int dat) {
// Keep track of a timer to determine when page program and erase
// cycles complete.
if (m_write_count > 0) {
if (0 == (--m_write_count)) {// When done with erase/page pgm,
m_sreg &= 0x0fc; // Clear the write in progress bit
if (m_debug) printf("Write complete, clearing WIP (inside SIM)\n");
}
}
if (csn) {
m_last_sck = 1;
m_ireg = 0; m_oreg = 0;
m_count= 0;
if ((QSPIF_PP == m_state)||(QSPIF_QPP == m_state)) {
// Start a page program
if (m_debug) printf("QSPI: Page Program write cycle begins\n");
if (m_debug) printf("CK = %d & 7 = %d\n", m_count, m_count & 0x07);
if (m_debug) printf("QSPI: pmem = %08lx\n", (unsigned long)m_pmem);
m_write_count = tPP;
m_state = QSPIF_IDLE;
m_sreg &= (~QSPIF_WEL_FLAG);
m_sreg |= (QSPIF_WIP_FLAG);
for(int i=0; i<256; i++) {
/*
if (m_debug) printf("%02x: m_mem[%02x] = %02x &= %02x = %02x\n",
i, (m_addr&(~0x0ff))+i,
m_mem[(m_addr&(~0x0ff))+i]&0x0ff, m_pmem[i]&0x0ff,
m_mem[(m_addr&(~0x0ff))+i]& m_pmem[i]&0x0ff);
*/
m_mem[(m_addr&(~0x0ff))+i] &= m_pmem[i];
}
m_quad_mode = false;
} else if (m_state == QSPIF_SECTOR_ERASE) {
if (m_debug) printf("Actually Erasing sector, from %08x\n", m_addr);
m_write_count = tSE;
m_state = QSPIF_IDLE;
m_sreg &= (~QSPIF_WEL_FLAG);
m_sreg |= (QSPIF_WIP_FLAG);
m_addr &= (-1<<16);
for(int i=0; i<(1<<16); i++)
m_mem[m_addr + i] = 0x0ff;
if (m_debug) printf("Now waiting %d ticks delay\n", m_write_count);
} else if (QSPIF_WRSR == m_state) {
if (m_debug) printf("Actually writing status register\n");
m_write_count = tW;
m_state = QSPIF_IDLE;
m_sreg &= (~QSPIF_WEL_FLAG);
m_sreg |= (QSPIF_WIP_FLAG);
} else if (QSPIF_CLSR == m_state) {
if (m_debug) printf("Actually clearing the status register bits\n");
m_state = QSPIF_IDLE;
m_sreg &= 0x09f;
} else if (m_state == QSPIF_BULK_ERASE) {
m_write_count = tBE;
m_state = QSPIF_IDLE;
m_sreg &= (~QSPIF_WEL_FLAG);
m_sreg |= (QSPIF_WIP_FLAG);
for(unsigned i=0; i<m_membytes; i++)
m_mem[i] = 0x0ff;
} else if (m_state == QSPIF_DEEP_POWER_DOWN) {
m_write_count = tDP;
m_state = QSPIF_IDLE;
} else if (m_state == QSPIF_RELEASE) {
m_write_count = tRES;
m_state = QSPIF_IDLE;
} else if (m_state == QSPIF_QUAD_READ_CMD) {
if ((m_mode_byte & 0x0f0)!=0x0a0)
m_quad_mode = false;
else
m_state = QSPIF_QUAD_READ_IDLE;
} else if (m_state == QSPIF_QUAD_READ) {
if ((m_mode_byte & 0x0f0)!=0x0a0)
m_quad_mode = false;
else
m_state = QSPIF_QUAD_READ_IDLE;
} else if (m_state == QSPIF_QUAD_READ_IDLE) {
}
m_oreg = 0x0fe;
return dat;
} else if ((!m_last_sck)||(sck == m_last_sck)) {
// Only change on the falling clock edge
// printf("SFLASH-SKIP, CLK=%d -> %d\n", m_last_sck, sck);
m_last_sck = sck;
if (m_quad_mode)
return (m_oreg>>8)&0x0f;
else
// return ((m_oreg & 0x0100)?2:0) | (dat & 0x0d);
return (m_oreg & 0x0100)?2:0;
}
// We'll only get here if ...
// last_sck = 1, and sck = 0, thus transitioning on the
// negative edge as with everything else in this interface
if (m_quad_mode) {
m_ireg = (m_ireg << 4) | (dat & 0x0f);
m_count+=4;
m_oreg <<= 4;
} else {
m_ireg = (m_ireg << 1) | (dat & 1);
m_count++;
m_oreg <<= 1;
}
// printf("PROCESS, COUNT = %d, IREG = %02x\n", m_count, m_ireg);
if (m_state == QSPIF_QUAD_READ_IDLE) {
assert(m_quad_mode);
if (m_count == 24) {
if (m_debug) printf("QSPI: Entering from Quad-Read Idle to Quad-Read\n");
if (m_debug) printf("QSPI: QI/O Idle Addr = %02x\n", m_ireg&0x0ffffff);
m_addr = (m_ireg) & m_memmask;
assert((m_addr & (~(m_memmask)))==0);
m_state = QSPIF_QUAD_READ;
} m_oreg = 0;
} else if (m_count == 8) {
QOREG(0x0a5);
// Figure out what command we've been given
if (m_debug) printf("SPI FLASH CMD %02x\n", m_ireg&0x0ff);
switch(m_ireg & 0x0ff) {
case 0x01: // Write status register
if (2 !=(m_sreg & 0x203)) {
if (m_debug) printf("QSPI: WEL not set, cannot write status reg\n");
m_state = QSPIF_INVALID;
} else
m_state = QSPIF_WRSR;
break;
case 0x02: // Page program
if (2 != (m_sreg & 0x203)) {
if (m_debug) printf("QSPI: Cannot program at this time, SREG = %x\n", m_sreg);
m_state = QSPIF_INVALID;
} else {
m_state = QSPIF_PP;
if (m_debug) printf("PAGE-PROGRAM COMMAND ACCEPTED\n");
}
break;
case 0x03: // Read data bytes
// Our clock won't support this command, so go
// to an invalid state
if (m_debug) printf("QSPI INVALID: This sim does not support slow reading\n");
m_state = QSPIF_INVALID;
break;
case 0x04: // Write disable
m_state = QSPIF_IDLE;
m_sreg &= (~QSPIF_WEL_FLAG);
break;
case 0x05: // Read status register
m_state = QSPIF_RDSR;
if (m_debug) printf("QSPI: READING STATUS REGISTER: %02x\n", m_sreg);
QOREG(m_sreg);
break;
case 0x06: // Write enable
m_state = QSPIF_IDLE;
m_sreg |= QSPIF_WEL_FLAG;
if (m_debug) printf("QSPI: WRITE-ENABLE COMMAND ACCEPTED\n");
break;
case 0x0b: // Here's the read that we support
if (m_debug) printf("QSPI: FAST-READ (single-bit)\n");
m_state = QSPIF_FAST_READ;
break;
case 0x30:
if (m_debug) printf("QSPI: CLEAR STATUS REGISTER COMMAND\n");
m_state = QSPIF_CLSR;
break;
case 0x32: // QUAD Page program, 4 bits at a time
if (2 != (m_sreg & 0x203)) {
if (m_debug) printf("QSPI: Cannot program at this time, SREG = %x\n", m_sreg);
m_state = QSPIF_INVALID;
} else {
m_state = QSPIF_QPP;
if (m_debug) printf("QSPI: QUAD-PAGE-PROGRAM COMMAND ACCEPTED\n");
if (m_debug) printf("QSPI: pmem = %08lx\n", (unsigned long)m_pmem);
}
break;
case 0x35: // Read configuration register
m_state = QSPIF_RDCR;
if (m_debug) printf("QSPI: READING CONFIGURATION REGISTER: %02x\n", m_creg);
QOREG(m_creg);
break;
case 0x9f: // Read ID
m_state = QSPIF_RDID;
if (m_debug) printf("QSPI: READING ID, %02x\n", (DEVID>>24)&0x0ff);
QOREG(0xfe);
break;
case 0xab: // Release from DEEP POWER DOWN
if (m_sreg & QSPIF_DEEP_POWER_DOWN_FLAG) {
if (m_debug) printf("QSPI: Release from deep power down\n");
m_sreg &= (~QSPIF_DEEP_POWER_DOWN_FLAG);
m_write_count = tRES;
} m_state = QSPIF_RELEASE;
break;
case 0xb9: // DEEP POWER DOWN
if (0 != (m_sreg & 0x01)) {
if (m_debug) printf("QSPI: Cannot enter DEEP POWER DOWN, in middle of write/erase\n");
m_state = QSPIF_INVALID;
} else {
m_sreg |= QSPIF_DEEP_POWER_DOWN_FLAG;
m_state = QSPIF_IDLE;
}
break;
case 0xc7: // Bulk Erase
if (2 != (m_sreg & 0x203)) {
if (m_debug) printf("QSPI: WEL not set, cannot erase device\n");
m_state = QSPIF_INVALID;
} else
m_state = QSPIF_BULK_ERASE;
break;
case 0xd8: // Sector Erase
if (2 != (m_sreg & 0x203)) {
if (m_debug) printf("QSPI: WEL not set, cannot erase sector\n");
m_state = QSPIF_INVALID;
} else {
m_state = QSPIF_SECTOR_ERASE;
if (m_debug) printf("QSPI: SECTOR_ERASE COMMAND\n");
}
break;
case 0x0eb: // Here's the (other) read that we support
// printf("QSPI: QUAD-I/O-READ\n");
m_state = QSPIF_QUAD_READ_CMD;
m_quad_mode = true;
break;
default:
printf("QSPI: UNRECOGNIZED SPI FLASH CMD: %02x\n", m_ireg&0x0ff);
m_state = QSPIF_INVALID;
assert(0 && "Unrecognized command\n");
break;
}
} else if ((0 == (m_count&0x07))&&(m_count != 0)) {
QOREG(0);
switch(m_state) {
case QSPIF_IDLE:
printf("TOO MANY CLOCKS, SPIF in IDLE\n");
break;
case QSPIF_WRSR:
if (m_count == 16) {
m_sreg = (m_sreg & 0x061) | (m_ireg & 0x09c);
if (m_debug) printf("Request to set sreg to 0x%02x\n",
m_ireg&0x0ff);
} else if (m_count == 24) {
m_creg = (m_creg & 0x0fd) | (m_ireg & 0x02);
if (m_debug) printf("Request to set creg to 0x%02x\n",
m_ireg&0x0ff);
} else {
fprintf(stderr, "QSPIFLASH-ERR: TOO MANY CLOCKS FOR WRR!!!\n");
exit(EXIT_FAILURE);
m_state = QSPIF_IDLE;
}
break;
case QSPIF_CLSR:
assert(0 && "Too many clocks for CLSR command!!\n");
break;
case QSPIF_RDID:
if (m_count == 32) {
m_addr = m_ireg & m_memmask;
if (m_debug) printf("READID, ADDR = %08x\n", m_addr);
QOREG((DEVID>>8));
if (m_debug) printf("QSPI: READING ID, %02x\n", (DEVID>>8)&0x0ff);
} else if (m_count > 32) {
if (((m_count-32)>>3)&1)
QOREG((DEVID));
else
QOREG((DEVID>>8));
if (m_debug) printf("QSPI: READING ID, %02x -- DONE\n", 0x00);
}
// m_oreg = (DEVID >> (2-(m_count>>3)-1)) & 0x0ff;
break;
case QSPIF_RDSR:
// printf("Read SREG = %02x, wait = %08x\n", m_sreg,
// m_write_count);
QOREG(m_sreg);
break;
case QSPIF_RDCR:
if (m_debug) printf("Read CREG = %02x\n", m_creg);
QOREG(m_creg);
break;
case QSPIF_FAST_READ:
if (m_count == 32) {
m_addr = m_ireg & m_memmask;
if (m_debug) printf("FAST READ, ADDR = %08x\n", m_addr);
QOREG(0x0c3);
assert((m_addr & (~(m_memmask)))==0);
} else if ((m_count >= 40)&&(0 == (m_sreg&0x01))) {
//if (m_count == 40)
//printf("DUMMY BYTE COMPLETE ...\n");
QOREG(m_mem[m_addr++]);
// if (m_debug) printf("SPIF[%08x] = %02x\n", m_addr-1, m_oreg);
} else m_oreg = 0;
break;
case QSPIF_QUAD_READ_CMD:
// The command to go into quad read mode took 8 bits
// that changes the timings, else we'd use quad_Read
// below
if (m_count == 32) {
m_addr = m_ireg & m_memmask;
// printf("FAST READ, ADDR = %08x\n", m_addr);
// printf("QSPI: QUAD READ, ADDR = %06x\n", m_addr);
assert((m_addr & (~(m_memmask)))==0);
} else if (m_count == 32+24) {
m_mode_byte = (m_ireg>>16) & 0x0ff;
// printf("QSPI: MODE BYTE = %02x\n", m_mode_byte);
} else if ((m_count > 32+24)&&(0 == (m_sreg&0x01))) {
QOREG(m_mem[m_addr++]);
// printf("QSPIF[%08x]/QR = %02x\n",
// m_addr-1, m_oreg);
} else m_oreg = 0;
break;
case QSPIF_QUAD_READ:
if (m_count == 32) {
m_mode_byte = (m_ireg & 0x0ff);
// printf("QSPI/QR: MODE BYTE = %02x\n", m_mode_byte);
} else if ((m_count >= 32+16)&&(0 == (m_sreg&0x01))) {
QOREG(m_mem[m_addr++]);
// printf("QSPIF[%08x]/QR = %02x\n", m_addr-1, m_oreg & 0x0ff);
} else m_oreg = 0;
break;
case QSPIF_PP:
if (m_count == 32) {
m_addr = m_ireg & m_memmask;
if (m_debug) printf("QSPI: PAGE-PROGRAM ADDR = %06x\n", m_addr);
assert((m_addr & (~(m_memmask)))==0);
// m_page = m_addr >> 8;
for(int i=0; i<256; i++)
m_pmem[i] = 0x0ff;
} else if (m_count >= 40) {
m_pmem[m_addr & 0x0ff] = m_ireg & 0x0ff;
// printf("QSPI: PMEM[%02x] = 0x%02x -> %02x\n", m_addr & 0x0ff, m_ireg & 0x0ff, (m_pmem[(m_addr & 0x0ff)]&0x0ff));
m_addr = (m_addr & (~0x0ff)) | ((m_addr+1)&0x0ff);
} break;
case QSPIF_QPP:
if (m_count == 32) {
m_addr = m_ireg & m_memmask;
m_quad_mode = true;
if (m_debug) printf("QSPI/QR: PAGE-PROGRAM ADDR = %06x\n", m_addr);
assert((m_addr & (~(m_memmask)))==0);
// m_page = m_addr >> 8;
for(int i=0; i<256; i++)
m_pmem[i] = 0x0ff;
} else if (m_count >= 40) {
m_pmem[m_addr & 0x0ff] = m_ireg & 0x0ff;
// printf("QSPI/QR: PMEM[%02x] = 0x%02x -> %02x\n", m_addr & 0x0ff, m_ireg & 0x0ff, (m_pmem[(m_addr & 0x0ff)]&0x0ff));
m_addr = (m_addr & (~0x0ff)) | ((m_addr+1)&0x0ff);
} break;
case QSPIF_SECTOR_ERASE:
if (m_count == 32) {
m_addr = m_ireg & 0x0ffc000;
if (m_debug) printf("SECTOR_ERASE ADDRESS = %08x\n", m_addr);
assert((m_addr & 0xfc00000)==0);
} break;
case QSPIF_RELEASE:
if (m_count >= 32) {
QOREG(DEVESD);
} break;
default:
break;
}
} // else printf("SFLASH->count = %d\n", m_count);
m_last_sck = sck;
if (m_quad_mode)
return (m_oreg>>8)&0x0f;
else
// return ((m_oreg & 0x0100)?2:0) | (dat & 0x0d);
return (m_oreg & 0x0100)?2:0;
}