How many UARTs can be emulated using FlexIO in S32K144?

[prasanna_rawke]

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.

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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

[dianabatrlova]

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

[prasanna_rawke]

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