KEAZN64 SPI CS Goes High inbetween packet

e1ali — Thu, 30 Mar 2023 17:59:31 GMT

Hello,

I'm currently interfacing with a device over SPI using the KEAZN64 microcontroller. I'm using Processor Expert in KDS for development, since the later NXP tools do not support the KEA line of micros. The device I'm interfacing with can operate up to 3.6Mhz. I've currently set the clock speed to 500KHz and I can interface over SPI just fine. When I increase the speed to 1MHz I'm seeing a small pulse on the CS line that breaks the existing code. I've attached a picture of a correct packet @500KHz and an incorrect packet @ 1MHz.

500 KHz:

1 MHz:

As you can see in the 1MHz picture, the CS line goes high after the 4th byte for some reason, but this doesn't happen when I run it at 500KHz.

I'm using PE in KDS to generate the SPI code, and here is the diff between 500KHz and 1MHz:

500KHz:

/* SPI0_BR: ??=0,SPPR=0,SPR=4 */
SPI0_BR = (SPI_BR_SPPR(0x00) | SPI_BR_SPR(0x04)); /* Set baud rate register */

1MHz:

/* SPI0_BR: ??=0,SPPR=0,SPR=3 */
SPI0_BR = (SPI_BR_SPPR(0x00) | SPI_BR_SPR(0x03)); /* Set baud rate register */

I'd appreciate any help!

Re: KEAZN64 SPI CS Goes High inbetween packet

CarlosGarabito — Tue, 04 Apr 2023 00:37:53 GMT

Sorry, we no longer support processor expert, neither KDS, we recommend you to switch to S32 Design Studio for Arm (https://www.nxp.com/design/software/development-software/s32-design-studio-ide/s32-design-studio-for-arm:S32DS-ARM)

topic Re: KEAZN64 SPI CS Goes High inbetween packet in Kinetis Microcontrollers

KEAZN64 SPI CS Goes High inbetween packet

Re: KEAZN64 SPI CS Goes High inbetween packet