P_UART and other questions for 20737S

[AnBa_330971]

1. P_UART question

There may be two sets of P_UART pins

• P32 (Tx) and P33 (Rx)
• P0 (Tx) and P2 (Rx)

I have used P32/P33 for debug traces.

Would it be possible to use the following set-ups at the same time?

• Use P32/P32 for debug traces
• Use P0/P2 to interface with an MCU

I would like to be able to print debug messages while running an UART on P0/P2 with MCU.

2. Pull-up on P1

Also I believe P1 needs to be pulled up for the internal EEPROM's I2C.  Are there any other pins that need to be pulled up?

3. Pull-down on HCI UART_RX

I believe that HCI UART_RX (Pin18) is pulled down internally.  Do I need to pull down with an external resistor (10k)?

The WICED Sense kit shows the Pin18 is pulled down via 10k to the ground.

4. nCS on P26

Does SPI2 master control this pin at all (active low)?

Or it is used only for SPI2 slave?

5. Best way to communicated with MCU

• P-UART
• SPI

I believe SPI would provide a faster transfer. 

P-UART may be easier to implement.  However, we have an SPI working between 20737 and MCU.  Does it still make sense to try to implement P-UART?

6. Schematic/layout review

Who can I contact for schematic/layout review in PM?

Thank you,

Andrew

[Anonymous · Accepted solution]

1) You can use only one PUART at a time.

2) No.

3) Yes. Pull down has to be connected

4)

5) Anything is fine.

6) Please contact Cypress Tech Support by creating a case.

[AnBa_330971]

Thanks Madhu.

One follow up question on PUART.

The fact that I can use only one PUART port at a time may work OK.

Here's a potential scenario

• HW connect P32 (Tx) and P33 (Rx) for debug
• HW connect P0 (Tx) and P2 (Rx) for communication with MCU
• Program CYW20737S with P32/P33 for PUART:  I can do most of debugging in this mode
• Re-program CYW20737S, this time with P0/P2 for PUART with MCU

The flexibility is still of high value to us because we then do not need to include jumpers to switch the PUART connectivity.

We can just re-program to use either of the PUART ports.

Could you confirm this?

Regards,

Andrew

[Anonymous]

Yes, you can reprogram to change the PUART pins.