LPC MicrocontrollersのトピックRe: LPC flash characteristics (erased state, erase/prog size, endurance, etc)

LPC flash characteristics (erased state, erase/prog size, endurance, etc)

phatpaul — Tue, 31 Jan 2023 17:26:31 GMT

Can someone at NXP please help me fill out this table? I'm trying to port my EEPROM emulation algorithm to support several LPC chips, and they seem to behave differently, even within the LPC8xx series.

Also please point me to the documentation of this if it exists.

LPCxx flash characteristics (erased state, erase/prog size, endurance, etc)

MCU Family	Flash erased state as read	Prog size min / max	Erase size min / max	Prog/erase endurance min
LPC802
LPC804	0x00	64B / 1024B	64B / 1024B	200,000
LPC81x
LPC82x
LPC83x
LPC84x	0xFF	64B / 1024B	64B / 1024B	10,000
others...

I found a note on LPC55xx that said that you shouldn't even be able to read erased (unprogrammed) flash (hard-fault!). Is this also true for LPC8x? https://community.nxp.com/t5/LPC-Microcontrollers-Knowledge/LPC55xx-Erased-Memory-State-0-or-1/ta-p/1135084

BTW, I've already found out that I can't write to the flash in units smaller than 64B page on LPC804: https://community.nxp.com/t5/LPC-Microcontrollers/LPC804-write-flash-single-word/m-p/1400358

A follow-up question: Based on my observations with LPC804, it seems that it is unnecessary to call "Erase page" before call "Copy RAM to flash" since the latter seems to erase the page before programming anyway. Is it recommended or would it count to unnecessary Prog/Erase cycles? Is this true for all LPC variants, or just LPC804?

Re: LPC flash characteristics (erased state, erase/prog size, endurance, etc)

Alice_Yang — Thu, 02 Feb 2023 09:15:06 GMT

Hello @phatpaul

1. About erase/program size, you can find in RMs, for example lpc802:

2. For "endurance", can find in DS:

3 "Is it recommended or would it count to unnecessary Prog/Erase cycles?"

->> Recommend erase before program, you can refer to IAP_FLASH demo under SDK, download SDK from: https://mcuxpresso.nxp.com/en/select

Alice

Re: LPC flash characteristics (erased state, erase/prog size, endurance, etc)

phatpaul — Thu, 02 Feb 2023 17:25:02 GMT

Thanks for your reply, Alice.

It is mainly the erased state that I'm asking for. I know I can get the other information from the documentation. Can you please tell me what is the erased state of flash memory for each of the LPC chips?

And can you even read the erased state?

Re: LPC flash characteristics (erased state, erase/prog size, endurance, etc)

Alice_Yang — Mon, 06 Feb 2023 06:57:16 GMT

Hello @phatpaul

If not specified, the default value after erase is 1, so first recommend check RM,

For lpc80x, you can get from RM, "The blank (erased) state of a page flash memory is a logic 0.".

You can also test on chip.

Alice