LPC MicrocontrollersのトピックRe: LPC SPI

LPC SPI

sveer9211 — Mon, 08 Oct 2018 04:07:13 GMT

Dear Sir,

I am currently working on the LPC1549 SPI protocol . i want to interface a SPI flash to the LPC1549

i am able to read the Manufacture ID and JEDEC ID but reading and writing of bytes or pages in not possible .

kindly give me some direction to proceed

Re: LPC SPI

jeremyzhou — Tue, 09 Oct 2018 03:11:48 GMT

Hi Lakhbir Singh,
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
I'd highly recommend you to visualize the SPI wave via the oscilloscope or logic analyzer when writing or reading SPI flash, then comparing with the standard process which is illustrated in SPI flash's datasheet, it will help you to figure the root cause out.
Have a great day,
TIC

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Re: LPC SPI

ianbenton — Wed, 10 Oct 2018 10:07:20 GMT

The usual trap for the unwary is the "write enable" command. This has to be sent before EVERY write instruction.

CS low - send 0x06 - CS high.

Then send the write command:

CS low - send 0x02, send the address, send the data - CS high.

Also, there is generally a limit on how much data you can send it one go.

And on SOME devices, pin 3 (Write protect) has a pull up, so you can leave it floating, and on OTHER devices it doesn't, so it won't write unless it is connected to V+.

Read isn't usually a problem, it will read 0xFF if it is new.

Re: LPC SPI

sveer9211 — Sat, 10 Nov 2018 04:30:36 GMT

thanks all for the reply i got SPI in working condition again thanks to all who responce in mean time .