S32K I/O SPEED too slow

[zhengjianfei]

HELLO，Recently I discovered  S32K's IO speed is not as fast as i wish。The CPU frq is 112Mhz，bus frq is 56Mhz。The IO speed is 130ns，that is 7.7MHZ。I was not use SDK but directly write the register  PDOR.As usually, IO Speed can reach the half of Bus frq.That is when bus frq is 56MHZ,io speed can reach 26Mhz.But S32K's is just 7.7MHz.Can S32K's io speed faster?

[danielmartynek]

Hello,

Could you please tell me the use case of such an implementation? If you want to generate a PWM signal or toggle GPIO for some timing purposes, you can use hardware peripherals.

There are many variables that influence the frequency. Number of instructions, prefetching, wait states on crossbar switch...

Regards,

Daniel

[zhengjianfei]

I use GPIO to drive a 16bit LCD。So I need GPIO as fast as it can。

[danielmartynek]

Hello,

I think you can get better results with LMEM Cache:

LMEM->PCCCR = 0x85000001;

Regards,

Daniel