i.MX RT Crossover MCUsのトピックRe: LPSPI1 Not Receiving data on MIMXRT1170EVKB

LPSPI1 Not Receiving data on MIMXRT1170EVKB

matt55354 — Thu, 05 Jun 2025 17:00:30 GMT

I'm using the MIMXRT1170EVKB dev board and attempting to read/write SPI data from the MX25L4006 flash over LPSPI1.

Problem: I can see data being sent to the flash (0x5a RDSFDP instruction) over SOUT, and I can see correct data returning from from the flash(on SIN), and the FIFO count(FSR_RXCOUNT) increments correctly, but the data from RDR_DATA ALWAYS reads 0. (the data on the physical line is NOT 0)

GPIO_AD_31Mux is set to 0 (LPSPI_SDI), and pad settings are default(0x6 on SW_PAD_CTL_PAD_GPIO_AD_31)

I'm confident clock phase and polarity are correct, since the data on the SIN line when decoded off the scope is the expected SFDP Signature( 0x53464450).

Other tidbits: I set SIN to a gpio, polling the level during a transaction, and was able to see the line changing the correct number of pulses, eliminating a suspicion of an unsoldered pad under the RT1176.

At this point, I'm suspecting an errata or a datasheet error. Any help would be appreciated!

Also, I attached a scope trace showing SCK, SIN, and SOUT.

Re: LPSPI1 Not Receiving data on MIMXRT1170EVKB

mayliu1 — Fri, 06 Jun 2025 03:39:45 GMT

Hi @matt55354 ,

Thank you so much for your interest in our products and for using our community.

I check your post about a scope trace showing SCK, SIN, and SOUT, but without SPI_PCS signal.

Could you please check LPSPI1_PCS0 signal by using a scope.

I search MX25L4006E datasheet for you, I find it describe that "When the device is not in operation and CS# is high, it is put in standby mode."

Wish it helps you.
If you still have question about it, please kindly let me know.

Wish you a nice day!

Best Regards
MayLiu

Re: LPSPI1 Not Receiving data on MIMXRT1170EVKB

matt55354 — Fri, 06 Jun 2025 14:11:09 GMT

Yes, I've previously verified CS# is functioning. This is apparent from the scope trace as the correct data is being returned from the chip on SIN. The problem is that reading RDR_DATA always returns 0.

Re: LPSPI1 Not Receiving data on MIMXRT1170EVKB

matt55354 — Fri, 06 Jun 2025 15:16:10 GMT

Just to be thorough, I'm attaching the scope shot with#cs0.

Re: LPSPI1 Not Receiving data on MIMXRT1170EVKB

matt55354 — Fri, 06 Jun 2025 17:29:35 GMT

For posterity, the solution was that LPSPI1_LPSPI_SDI_SELECT_INPUT daisy chain was not set to point to pin GPIO_AD_31. After finding this, everything is working as expected. Thanks to Ramdas Chary from Arrow Electronics for the hint on this.