AN408 - A Design Guide to SPI F-RAM Processor Companion - FM33256B

Overview

The FM33256B product offers an Integrated Processor Companion, Real Time Clock (RTC), and F-RAM memory. The processor companion comprises a power-on system reset, low-voltage detect, automatic switchover to backup power, a watchdog timer, an early power fail warning, two event counters, and a lockable 64-bit serial number. The FM33256B device has 256-Kbit of nonvolatile F-RAM memory. It employs an industry-standard SPI interface which is used to access the memory, the processor companion, and the RTC. The FM33256B operates over a 2.7 V to 3.6 V power supply range with the maximum SPI frequency of 16 MHz. It is available in a SOIC-14 package.