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dsicon
- 5th February 2021, 19:16
So I was writing to EE when I started to worry about the endurance of the EE as there would be frequently writes potentially.
As I pursued that in the data sheet without much luck I accidentally stumbled on the fact that my chip has no EE !

I was shocked as I had never encountered a PIC that did not have EE and I guess I just assumed that this one did when I picked it, I only use a few bytes.
Obviously a gross oversight on my part.
This raises two questions:
Should the compiler have been aware that the chip had no EE? It was perfectly happy, I would have thought there might be an error.
Or maybe that is beyond the scope of the compiler?

Secondly now I need a drop in chip with EE, my original part is
PIC16F15376T-I/PT
44/TQFP
My app is simple, all digital, no special peripherals needed. My code is all done and running so minimal recoding would be nice.
INTOSC 30MHz
Any part suggestions greatly appreciated.

aerostar
- 6th February 2021, 10:29
This has according to https://www.microchip.com/wwwproducts/en/PIC16F15376

Flash Program Memory with self read/write capability, so you could use space at the end of the flash program memory for your data.

Alternatively why not use a 24lc64 or similar memory chip on your board

mpgmike
- 6th February 2021, 17:40
Microchip has a cool site to filter through all their offerings. Several PICs meet your criteria. Here is the link:

https://www.microchip.com/ParamChartSearch/chart.aspx?branchID=30048

dsicon
- 6th February 2021, 19:35
This has according to https://www.microchip.com/wwwproducts/en/PIC16F15376

Flash Program Memory with self read/write capability, so you could use space at the end of the flash program memory for your data.

Alternatively why not use a 24lc64 or similar memory chip on your board
Adding an external chip would require re-spinning the pcb. I thought about using WRITECODE and that might work but I worry about the endurance as I would like to write many times.

dsicon
- 6th February 2021, 19:40
Microchip has a cool site to filter through all their offerings. Several PICs meet your criteria. Here is the link:

https://www.microchip.com/ParamChartSearch/chart.aspx?branchID=30048
thanks for that, what is "Emulated EEPROM in Flash" ?

mpgmike
- 7th February 2021, 18:41
High Endurance Flash (HEF).

EEPROMs have a limited number of times they can be written to; they can be read from infinitely, though. Flash has a VERY limited number of writes before it begins to corrupt the data. HEF is Flash, but is designed to be more robust than normal Flash. Using the Flash Write procedure, you can use HEF like you would EEPROM (almost).

Flash works differently than EEPROM in that you must erase entire blocks at a time. You cannot simply write to a single address repeatedly. Normal EEPROM procedures in PCB don't work with HEF. Read up on it.

I would suggest if you need to write to EEPROM addresses randomly & repeatedly, use a PIC with a genuine EEPROM.

Ioannis
- 7th February 2021, 20:36
I know you don't want to re-wire your board but serial SRAM is a good solution for no limit in writing but needs a battery backup to hold the data.

aerostar
- 8th February 2021, 10:11
24LC series is a possibility and does not need battery backup.

Serial EEPROM
• More than 1 Million Erase/Write Cycles - if that is enough
• Data Retention > 200 years

Ioannis
- 8th February 2021, 10:25
That million is valid for block write though...

tumbleweed
- 8th February 2021, 17:39
and that might work but I worry about the endurance as I would like to write many times
So, what's your definition of "many times", and when you say "I only use a few bytes" how many bytes is that?

Dave
- 10th February 2021, 15:19
If it was me, I would use an FM24W256 as it is a 256-Kbit ferroelectric random access memory (F-RAM)
logically organized as 32 K × 8. It has an unlimited write cycle and does NOT have the 5 Millisecond delay to write. I have used these in many projects that record data.
Dave Purola,
N8NTA
EN82fn