topic Re: How many UARTs can be emulated using FlexIO in S32K144? in S32K

How many UARTs can be emulated using FlexIO in S32K144?

prasanna_rawke — Wed, 06 May 2020 04:50:30 GMT

S32K144 has a option to configure 8 pins as FlexIO data pins. On the other hand, it has 4 shifters and 4 timers as per the datasheet.

And one FlexIO UART TX requires, one shifter and one timer for the operation.

--------------------------------------------------------------------------------------------------------------------

Does it mean that we can emulate only two duplex UARTs (Rx+Tx) using FlexIO?

Is there any way to implement 4 UARTs using FlexIO? For example, in my application, I can keep the baudrate of all UARTs same, which can reduce the number of timers required.

Regards,

Prasanna

Re: How many UARTs can be emulated using FlexIO in S32K144?

dianabatrlova — Thu, 07 May 2020 09:32:08 GMT

Hello Prasanna,

As you write, the FlexIO has available 4 Timers, 4 Shifters, 8 Pins

For one UART (TX + RX) 2 shifters and 2 timers are needed.
So, we can configure max 2x UART by FlexIO.

There is a possibility to have several shifters clocked by the same timer but still, we have only 4 shifters.

However, the S32K144 has 3x LPUART, you could use it.

I hope it helps.

Best regards,

Diana

Re: How many UARTs can be emulated using FlexIO in S32K144?

prasanna_rawke — Thu, 07 May 2020 09:38:36 GMT

Hello Diana,

Thanks for the clarification.

Actually in my application, all the LPUARTs are already consumed by other modules, and I was going by the impression that 8 FlexIO data pins will cater 4 additional UARTs.

Thanks,

Prasanna