STM32F302: SPI data register not changing on write for certain modes

[Sanjay_Periyasamy]

Hi,
While using the SPI2 for transmitting a data in STM32F302R8, the transmitting data reflects in the DATA register only in the CPOL = 0(Low) and CPHA = 0(1st edge). In the other modes (CPOL and CPHA) the data is not reflecting in the DATA register.

My configurations:

Mode: Full-Duplex Master

Basic Parameters:
Frame Format: Motorola
Data Size: 8 Bits
First Bit: MSB first

Clock Parameters:
Prescaler (for Baud Rate):2
Baud Rate: 16.0 MBits/s
Clock Polarity (CPOL): High
Clock Phase (CPHA): 2 Edge

Advanced Parameters
CRC Calculation: Disabled
NSS Signal Type: Output Hardware (I tried for both Output Hardware and NSS signal type: Disable)

What might be problem with my configurations?

Here are my observations:

#	CPOL	CPHA	Status in DATA register
Mode 1	Low	Edge 1	Data reflected correctly
Mode 2	Low	Edge 2	Wrong data reflected
Mode 3	High	Edge 1	No data reflected
Mode 4	High	Edge 2	No data reflected

Also, it is not mentioned in the errata either.

Has anyone faced this? Kindly help me with this.

Best regards,

Sanjay

[KDJEM.1]

Hello @Sanjay_Periyasamy and welcome to the Community,

 

Make sure that the CPOL and CPHA settings are correctly applied while the SPI is disabled.

Did you get a Hardfault or error_Handler?

 

Thank you.

Kaouthar

[Sanjay_Periyasamy]

Hi @KDJEM.1 

Thanks for the response.

Actually, I have checked CPHA and CPOL bits in the corresponding and those bits were set correctly.

And also, I didn't get any Hardfault error.

MAIN ISSUE

The transferring data alone doesn't reflect in the data register for the Mode 3 and 4.