S32KのトピックRe: SPI problem when changing to a higher frequency

SPI problem when changing to a higher frequency

emmanuelaguilas — Thu, 15 Feb 2018 16:06:40 GMT

I'm running SPI at 1MHz speed on EVB board with a polling method similar to the one on S32DS example, but for continuous transmission of 256 bytes. When I change the speed to 10MHz some data bytes I receive at my beagle are distorted (if I was sending 0x55 for all bytes, I received a different value on some of them), seem to be the SPI lines are quite noise. Is there a hardware change that need to be done for higher frequencies or is the the EVB capable of handling that frequency?

Re: SPI problem when changing to a higher frequency

danielmartynek — Thu, 15 Feb 2018 22:03:04 GMT

Hi,
The MCU supports 10MHz SPI baud rate which is the fastest rate in Run Mode without the loopback option (Table 31 of the S32Kxx Data sheet).
Please note that the measurements were taken with fastest slew setting PORT_PCRn[DSE = 1] (Table 12, 13 of the DS).
So please use high-drive pins, labeled as GPIO-HD in S32K144_IO_Signal_Description_Input_Multiplexing.xlsx
Regarding EVB, I don’t see any problem with that.

Regards,
Daniel