Intel Atom C2000 Rangeley UART-SMBUS Multiplexing

[idata]

In Atom Processor C2000 family,we are using C2338 part.

In the C2000 spec update by intel,it is mentioned in the errata no AVR3,"Disabling One UART Disables Both UARTs"

No fix is there for this errata.

Out of the two multiplexed UARTs,Our requirement is to use one UART & other for SMBUS2 interface.

UART0 is multiplexed with SMBUS & has control register to enable or disable.

Also the CFIO_REGS_PAD_SMB_DATA2_PCONF0 is used to select the UART0 or SMBUS functionality.

Selecting the UART0 Control register to its default value(ie. 1b = enable)& changing the IO select register to select the SMBUS

cause any conflicts? As we need the SMBUS2 for reading the processor die temperature.

The UART1 which is multiplexed with GPIO, we plan to use as UART interface only for connecting a LCD display.

So kindly let us know, is this errata applicable to all other SKUs of C2000?

Advice us the implementation of our requirement related to this errata AVR3.

[WILLIAM_C_Intel]

Hello, Sankar! I am sorry that we do not have an answer to provide yet, but we are trying to find a subject matter expert to help answer your question. Please be patient.

[Natalie_Z_Intel]

Hello, sankar! I was able to track down this response from someone on the Rangeley team: "The SMBus2 Unit 2 interface uses as PECI over SMBus and shared function and signals with UART0. Even the signal pins are set to use as SMBus, the UART0 function should not be disable (refer to errata AVR3). As SoC default, the SMBus is selected when power on. Then SW enable the UART for both ports. This will allow to use UART1 and SMBus2 PECI."

[idata]

Thank you Lynnz....

[Natalie_Z_Intel]

You are very welcome, Sankar. I am happy to help. Have a wonderful day!