SLAA649G October 2014 – August 2021 MSP430F2001 , MSP430F2002 , MSP430F2003 , MSP430F2011 , MSP430F2012 , MSP430F2013 , MSP430F2013-EP , MSP430F2101 , MSP430F2111 , MSP430F2112 , MSP430F2121 , MSP430F2122 , MSP430F2131 , MSP430F2132 , MSP430F2232 , MSP430F2234 , MSP430F2252 , MSP430F2254 , MSP430F2272 , MSP430F2274 , MSP430F2274-EP , MSP430F233 , MSP430F2330 , MSP430F235 , MSP430F2350 , MSP430F2370 , MSP430F2410 , MSP430F2416 , MSP430F2417 , MSP430F2418 , MSP430F2419 , MSP430F247 , MSP430F2471 , MSP430F248 , MSP430F2481 , MSP430F249 , MSP430F249-EP , MSP430F2491 , MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619 , MSP430F2619S-HT , MSP430FR2032 , MSP430FR2033 , MSP430FR2110 , MSP430FR2111 , MSP430FR2153 , MSP430FR2155 , MSP430FR2310 , MSP430FR2311 , MSP430FR2353 , MSP430FR2355 , MSP430FR2433 , MSP430FR2475 , MSP430FR2476 , MSP430FR2532 , MSP430FR2533 , MSP430FR2632 , MSP430FR2633 , MSP430FR2672 , MSP430FR2673 , MSP430FR2675 , MSP430FR2676 , MSP430FR4131 , MSP430FR4132 , MSP430FR4133 , MSP430G2001 , MSP430G2101 , MSP430G2102 , MSP430G2111 , MSP430G2112 , MSP430G2121 , MSP430G2131 , MSP430G2132 , MSP430G2152 , MSP430G2153 , MSP430G2201 , MSP430G2202 , MSP430G2203 , MSP430G2210 , MSP430G2211 , MSP430G2212 , MSP430G2213 , MSP430G2221 , MSP430G2230 , MSP430G2230-EP , MSP430G2231 , MSP430G2231-EP , MSP430G2232 , MSP430G2233 , MSP430G2252 , MSP430G2253 , MSP430G2302 , MSP430G2302-EP , MSP430G2303 , MSP430G2312 , MSP430G2313 , MSP430G2332 , MSP430G2332-EP , MSP430G2333 , MSP430G2352 , MSP430G2353 , MSP430G2402 , MSP430G2403 , MSP430G2412 , MSP430G2413 , MSP430G2432 , MSP430G2433 , MSP430G2444 , MSP430G2452 , MSP430G2453 , MSP430G2513 , MSP430G2533 , MSP430G2544 , MSP430G2553 , MSP430G2744 , MSP430G2755 , MSP430G2855 , MSP430G2955 , MSP430I2020 , MSP430I2021 , MSP430I2030 , MSP430I2031 , MSP430I2040 , MSP430I2041
The F2xx family flash controller is replaced by the FRAM controller in the FR4xx family.
The most significant differences between using FRAM and flash pertain to (1) timing and (2) power requirements (see Table 7-3).
Parameter | FRAM (FR4133)(1) | Flash (F2274)(1) |
---|---|---|
Program time for byte or word (maximum) | 120 ns | 116 µs (approximately) |
Erase time for segment (maximum) | Not applicable (pre-erase not required) | 18 ms |
Supply current during program (maximum) | No extra current during write (included in active power specification) | 5 mA |
Supply current during erase (maximum) | Not applicable (pre-erase not required) | 7 mA |
Nonvolatile memory maximum read frequency | 8 MHz | 16 MHz |
Because every read from an FRAM location is also a write, there is no current penalty due to write or erase. Hence, the power consumption when writing to a block of FRAM is the same as when reading from it. This is different from flash, where the writing process consumes excess power due to the operation of a device-internal charge pump. Similarly, FRAM does not require an erase before write and is not segmented like flash. Hence, there is no added erase current (or erase time) when writing to FRAM.
In terms of the write time, FRAM is written in four-word blocks, and the write time is built into each read cycle. Hence, there is no difference between the read time and write time for an FRAM byte, word, or 4‑word block. With regards to the read frequency, FRAM accesses (both read and write) are capped at 8 MHz. However, flash reads can take place at the maximum speed allowed by the device (fSYSTEM), which is 16 MHz in the F2xx devices.
The speed of instruction execution in an FRAM-based system is affected by the architecture. The FR4xx uses a cache-based architecture that employs a combination of register and FRAM accesses when executing from nonvolatile memory. This allows the system throughput to be higher than the maximum allowable read frequency of 8 MHz.