• SPI-Flash-Model
  • Features
    • Limits
  • Releases
  • Emulated Flash
  • How to use
    • API
      • Init
      • Dump
      • Store
      • Load
      • Compare
      • SFM (Spi Flash Model)
    • Example
  • References

SPI-Flash-Model

Arbitrary SPI Flash C model. With the scope of an SPI Flash driver unit test emulates this module SPI Flashes on logic level.

Features

The model emulates an SPI Flash on logic level. As input are SPI packets used. In a real world application would be sent this SPI packet to the physically SPI core instead.

Limits

• No timing behavior
  • emulated with WIP poll constant

Releases

Version	Date	Source	Change log
latest		latest.zip
v0.1.0	2023-04-01	v0.1.0.zip	initial draft

Emulated Flash

• W25Q16JV

How to use

The unittest gives a good flavor how to use the model.

API

To interact with the sfm (SPI Flash Model) are the following functions available.

Init

Initializes the SFM and selects the emulated flash.

int sfm_init (t_sfm *self, char flashType[]);

Dump

Dumps Flash memory in hex values to console. Setting of start/stop -1 will print whole memory content to console.

int sfm_dump (t_sfm *self, int32_t start, int32_t stop);

Store

Stores flash model internal data buffer as file. Supported formats:

• .dif : difference to empty flash 0xff in ascii-hex format

int sfm_store (t_sfm *self, char fileName[]);

Load

Restore flash model internal data buffer from File. Supported formats:

• .dif : difference to empty flash 0xff in ascii-hex format

int sfm_load (t_sfm *self, char fileName[]);

Compare

Compares SFM internal flash buffer with file. Supported formats:

• .dif : difference to empty flash 0xff in ascii-hex format

int sfm_cmp (t_sfm *self, char fileName[]);

SFM

Access SPI Flash memory. SPI request and response are placed in the same SPI buffer variable.

int sfm (t_sfm *self, uint8_t* spi, uint32_t len);

Example

The c snippet below shows an minimal example to interact with the sfm. The variable spi represents the packet sent to the SPI flash.

#include <stdlib.h> // EXIT codes, malloc
#include <stdio.h>  // f.e. printf
#include <stdint.h> // defines fixed data types: int8_t...
#include "spi_flash_model.h"  // function prototypes

int main ()
{
  /* variables */
  uint8_t spi[10];  // spi packet to interact with sfm
  t_sfm   spiFlash; // handle to SPI Flash

  /* define used flash model */
  sfm_init (&spiFlash, "W25Q16JV");

  /* write enable */
  spi[0] = 0x06;            // W25Q16JV: write enable instruction
  sfm (&spiFlash, spi, 1);  // access flash model

  /* write page */
  spi[0] = 0x02;  // W25Q16JV: write page instruction
  spi[1] = 0x00;  // address high byte
  spi[2] = 0x00;  // address middle byte
  spi[3] = 0x00;  // address low byte
  spi[4] = 0x01;  // data
  spi[5] = 0x23;
  spi[6] = 0x45;
  spi[7] = 0x67;
  spi[8] = 0x89;
  spi[9] = 0xAB;
  sfm (&spiFlash, spi, 10); // access flash model
    // poll for WIP
  for ( uint8_t i = 0; i < SFM_WIP_RETRY_IDLE; i++ ) {
    spiLen = 2;
    spi[0] = 0x05;
    sfm(&spiFlash, spi, spiLen);  // read state reg, needed for WIP poll
  }

  /* dump current flash content to check write */
  sfm_dump (&spiFlash, 0x0, 0x10);

  /* normal end */
  exit(0);
}

This example compiled and executed leads to following output:

gcc -c -O spi_flash_model.c -o spi_flash_model.o
gcc -c -O main.c -o main.o
gcc spi_flash_model.o main.o -lm -o main

./main

00: 01 23 45 67 89 ab ff ff  ff ff ff ff ff ff ff ff
10: ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff

References

• W25Q16JV