Fujitsu MB85 FRAM

Simple wrapper around I²C (i2c-bus) implementation to provide read / write capability.

API

Construction is achived via the statis from and fromId methods of MB85RC.

const id = ... // detected via I²C, or user specified 
const fram = MB85RC.fromId(bus, id)

Feature string

The feature set exposed as the Fujitsu product codes.

size

The density expressed as numeric value.

densityHuman

The density expressed as prodcut code string (example: '1M', '512K', ect)

busHuman

The bus as product code string ('RC' for I²C)

read(offset, length)

Direct access to read at an offset for desired length. Retruning a Promise that resolves to a Buffer.

write(offset, buffer)

Direct write to an offset given a buffer of desired length to be writen. Returning a Promise that resolves when completed.

Devcie ID

The provided library is also provides a way of identifying a chip based on its assigned Id value.

This can be passed in, however, it becomes more usefull with the bus level deviceId call. This uses a bus level discovery not supported by most chips. By using this method, the chips feature inforamtion can detected.

const i2c = require('i2c-bus')
const { I2CAddressedBus } = require('@johntalton/and-other-delights')
const { MB85RC, DEFAULT_MB85_ADDRESS } = require('@johntalton/mb85')

const busNumber = 1
const busAddress = DEFAULT_MB85_ADDRESS // 0x50

const bus1 = await i2c.openPromisified(busNumber)
const id = await bus1.deviceId()
const ab = new I2CAddressedBus(bus1, busAddress)
const fram = MB85RC.fromId(ab, id)

console.log('Fujitsu FRAM MB85', fram.busHuman, fram.densityHuman, fram.featuresHuman)
// Fujitsu FRAM MB85 RC 256K V