RTOS/SIMPLELINK-WIFI-CC3120-SDK-PLUGIN: Wifi failed when using SPI 1 of the MSP432E to connect to the SPI of the CC3120. Wifi work fine if SPI 2 or SPI 3 is used.

Tool/software: TI-RTOS

DESCRIPTION OF THE PROBLEM:

Using the MSP-432E401Y and CC3120BOOST, varied that with SPI 2, or SPI 3 connection to the SPI signals of the CC3120, Wifi works, but not work if SPI 1 is used.

SDK version used:
Simplelink_msp432e4_sdk_2_30_00_14
Simplelink_sdk_wifi_plugin_2_40_00_22

PROCEDURE to IDENTIFY THE PROBLEM:

STEP1: verify Wifi works fine with SPI 2 and SPI 3
The MSP-EXP432E401Y board has two locations for the CC3120BOOST to be plugged in:
- Location close to the Ethernet connector U14 has SPI 3 of the MSP432E connecting to the SPI of the CC3120
- Location away from U14 has SPI 2 of the MSP432E connecting the SPI of the CC3120.

I could make simple modifications in the code to make Wifi work in both SPI 2, and SPI 3.

STEP 2: Verify Wifi not work with SPI 1.
With SPI 3 the following shows the relevant connections between the MSP432E and the CC3120

CC3120                   MSP432E
SPI_CLK                 PQ0 (SPI 3)
SPI_MOSI               PQ2  (SPI 3)
SPI_MISO               PQ3 (SPI 3)
SPI_CS                  PP5
IRQ                         PM7
nHIB                       PD4

Lift the pins and use short jumpers to change the connections using SPI 1
CC3120                   MSP432E
SPI_CLK                 PB5 (SPI 1)
SPI_MOSI               PE4  (SPI 1)
SPI_MISO               PE5 (SPI 1)
Keep the rest of signals the same as above.

Modify the code to use SPI 1. Wifi detection failed. Using logic analyzer, I could see the communication on the SPI 1 bus at the beginning, but the communication shut down shortly.

QUESTIONS:

- I am suspicious that  this problem causes by a bug in the SPI 1 driver. Or there is some information I need to know when I use SPI 1.

Thank you.

Long