MSP430 Spy-Bi-Wire interface IC? - Page 1
Forum section: electronics / general

author: pacmann
author_rank: Contributor
timestamp: June 10, 2025, 10:04:20 am
content: I want to add a debugger and programmer in my custom board for the MSP430FR micro. Are there Spy-Bi-Wire to USB chips available? What is the cheapest way to program blank MSP430FR micros directly from Code Composer?

author: RoGeorge
author_rank: Super Contributor
timestamp: June 10, 2025, 10:23:40 am
content: Cheapest would be to buy a devbord from TI:https://www.ti.com/tool/MSP-EXP430FR2355Once in a while, they have promotions for their smaller "LaunchPad" devboards, usually at $4.30 a devboard, with USB programmer/debugger, and a microcontroller included. All their devboards can work directly from CCS, for program and debug. MSP430FR is a microcontroller family, MSP430 with internal FRAM instead of RAM, and the MCUs come in many sizes. FRAM is nice because it can retain data while unpowered, and it is also as fast as RAM, not slow like FLASH.As a side note, FRAM wear out not only when writing, but also when reading it. Don't worry, the wear is very low, for exampel if you make the smallest loop to repeatedly read from the same location, it will wear out only after a couple of years of non-stop reading from the same cell. In practice you would probably never wear out the FRAM.

author: josip
author_rank: Regular Contributor
timestamp: June 10, 2025, 07:07:50 pm
content: Quote from: pacmann on June 10, 2025, 10:04:20 amCheapest way to program blank MSP430FR is by BSL with USB-UART bridge. For this on PC side (any OS) can be used open source TI BSL Scripter, not sure about CCS.If just updating firmware by SBW is enough for you without break-point debugging than open source TI Replicator (slau320) can be used for this.If you want your own custom SBW also with break-point debugging than TI MSP (eZ)FET based on MSP430F5528/5529 with open firmware (MSPDS) and PC side (msp430.dll on any OS) can be used. If you want to go deeper than you can buy 5529 launchpad (as I did) and debug (5528 master) debugger (5529 target) to see how it is done on low level. BTW 5529 LP can be used also as dual debugger by one USB cable (there is USB HUB IC on board).Your target device is FR where job is done by using only quick read/write SBW functions, without need for precise timing like in flash case, so it is not big problem to port it on some low cost mcu that will be used as SBW master.Anyway, whatever you want, TI hardware/software related to SBW is open source and can be download from TI website.Quote from: RoGeorge on June 10, 2025, 10:23:40 amIt was never clear to me why TI used this as main advance over flash, because there are wait state with FRAM, and TI F5xx/6xx familly flash with block write over 250 kbyte/s was not slow at all. There is no wait states with F5xx/6xx and code executed (even overclocked) from RAM / flash take exactly same time.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 15, 2025, 05:34:56 am
content: Quote from: RoGeorge on June 10, 2025, 10:23:40 amThis was new to me. And now I do worry.Datasheet of fm18l08 states "unlimited read/write cycles".https://html.duckduckgo.com/html?q=fm18l08+datasheet+pdfFinding another datasheet:https://www.infineon.com/dgdl/Infineon-CY15B108QI_CY15V108QI_Excelon(TM)_LP_8-Mbit_(1024K_X_8)_Serial_(SPI)_F-RAM-DataSheet-v14_00-EN.PDF?fileId=8ac78c8c7d0d8da4017d0ee73ee37021Which does indeed specify a limit:The CY15X108QI is capable of supporting 10^^15 read/write cycles,And that's a big number. Assuming one million cycles per second, it would last:>>> 10e15/1e6/3600/24/365 = 317 years.

author: RoGeorge
author_rank: Super Contributor
timestamp: June 15, 2025, 06:59:38 am
content: Yes, the reading wear out of FRAM was not pointed out very clearly, but it was specified somewhere in the MSP430FR documentation.My understanding was that FRAM was a Texas Instruments technology, and a copyrighted name (maybe I was wrong?), so I'm surprised FRAM is used now by other manufacturers, too.Anyway, the numbers I was talking were about the first FRAMs made by Texas Instruments (in MSP430FR), and I remember their FRAM wear out to be in the range of years to decades at best, depending on how you count, but it was certainly not hundreds of years. I didn't check if the current MSP430FR still has the same FRAM wear out as the first ones.

author: Warhawk
author_rank: Frequent Contributor
timestamp: June 15, 2025, 08:10:34 am
content: Quote from: pacmann on June 10, 2025, 10:04:20 amIf I am not mistaken, you should be able to implement EZFET on your board:https://www.ti.com/lit/ug/slau647o/slau647o.pdf?ts=1749974725807&ref_url=https%253A%252F%252Fwww.google.com%252Fhttps://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430_ezFETLite/latest/index_FDS.htmlTI should be able to help with more details over the E2E forum. Questions go typically directly to application engineers that support the part.I hope this helps.

author: westfw
author_rank: Super Contributor
timestamp: June 15, 2025, 10:45:38 pm
content: QuoteThings are spelled out in this document:https://www.ti.com/lit/an/slaa526a/slaa526a.pdf?ts=1749976829137The "read" of an FRAM cell is destructive, like DRAM, and so requires a re-write after each read (done automatically), and thus reads and writes both have an effect on endurance.TI apparently doesn't have full data on when FRAM actually wears out (it takes too long), but they specify "at least 1015write/erase cycles" and 8MHz access speed, so I think that works out to about 4 years minimum endurance. The paper referenced above says 36years for a pessimal code example on an MSP430, since there is some cache memory that prevents every memory access from actually accessing the FRAM. Also, the endurance isper cell, and normal code will not be accessing the same cell at full speed.I wonder if there is more recent data - the first FRAM devices apparently came out ~2014, so ...

author: RoGeorge
author_rank: Super Contributor
timestamp: June 16, 2025, 06:14:21 am
content: Didn't notice this at the first read (10+ years ago), but high temperatures can also erase the data:Quotequote fromhttps://www.ti.com/lit/an/slaa526a/slaa526a.pdfThe slaa526 TI Application Report describes FRAM as based on ferroelectric materials. Ferroelectric materials are expected to also be pyroelectric and piezoelectric:Quotequote fromhttps://en.wikipedia.org/wiki/FerroelectricityThere is already a note about reflow temperature affecting MSP430FR57xx (not sure why only for MSP430FR57xx and not for all FRAM), but I'll be curious, too, about the second property, the piezoelectric property of ferroelectric materials.Would this make FRAM data retention vulnerable to mechanical shocks, too? (I suspect it might be so)