Code to interact with BRCF016GWZ

EEPROM.cpp

#include "EEPROM.h"

extern I2C i2c;

namespace EEPROM {

void resetEEPROM() {
    char buff[MAX_BLOCK_WRITE];
    for (uint16_t i = 0; i < MAX_BLOCK_WRITE; i++) {
        buff[i] = 0xFF;
    }
    for (uint16_t i = 0; i < EEPROM_SIZE; i += MAX_BLOCK_WRITE) {
        writeBlock(i, buff, MAX_BLOCK_WRITE);
    }
}

void dumpEEPROM() {
    char buff[32]; // size determines cells per line
    printf("Dumping EEPROM...\n");
    for (uint16_t i = 0; i < EEPROM_SIZE; i += sizeof(buff)) {
        printf("%04X : ", i);
        readBites(i, buff, sizeof(buff));
        for (int j = 0; j < sizeof(buff); j++) {
            printf("%X ", buff[j]);
        }
        printf("\n");
    }
}

void readBites(uint16_t addr, char* dest, uint16_t length) {
    if (addr + length > EEPROM_SIZE) {
        return; // not enough memory!
    }
    while (i2c.write(ID, NULL, 0) != 0); // wait until chip is ready
    char c = addr & 0xFF;
    i2c.write(ID | (PAGE_MASK & (addr >> 7)), &c, 1);
    i2c.read(ID, dest, length);
}

void writeBites(uint16_t addr, char* data, uint16_t length) {
    if (addr + length > EEPROM_SIZE) {
        return; // not enough memory!
    }
    // write until page aligned
    uint16_t to_page_length = ((addr + MAX_BLOCK_WRITE - 1) / MAX_BLOCK_WRITE) * MAX_BLOCK_WRITE - addr;
    if (length <= to_page_length) {
        writeBlock(addr, data, length);
        return; // no more bytes to write
    }
    writeBlock(addr, data, to_page_length);
    addr += to_page_length;
    data += to_page_length;
    length -= to_page_length;
    // now we can write MAX_BLOCK_WRITE at a time
    while (length >= MAX_BLOCK_WRITE) {
        writeBlock(addr, data, MAX_BLOCK_WRITE);
        addr += MAX_BLOCK_WRITE;
        data += MAX_BLOCK_WRITE;
        length -= MAX_BLOCK_WRITE;
    }
    writeBlock(addr, data, length);
}

void writeBlock(uint16_t addr, char* data, uint16_t length) {
    while (i2c.write(ID, NULL, 0) != 0);
    char buff[length + 1];
    buff[0] = addr & 0xFF;
    memcpy(buff + 1, data, length);
    i2c.write(ID | (PAGE_MASK & (addr >> 7)), buff, length + 1);
}

}

EEPROM.h

#ifndef EEPROM_H
#define EEPROM_H

#include "mbed.h"

namespace EEPROM {

// For BRCF016GWZ
const uint8_t ID = 0b10100000; // left 4 bits is ID
const uint8_t PAGE_MASK = 0b00001110; // 3 bits determines page
const uint16_t EEPROM_SIZE = 2048; // bytes
const uint8_t MAX_BLOCK_WRITE = 16; // bytes, size of pages

void resetEEPROM(); // call this if changing size of data structure stored
void dumpEEPROM();
void readBites(uint16_t addr, char* dest, uint16_t length);
void writeBites(uint16_t addr, char* data, uint16_t length);
void writeBlock(uint16_t addr, char* data, uint16_t length);

}

#endif