Issues that need attention when initializing SPI of TI C2000 series 280049 chip

Jacktang

Issues that need attention when initializing SPI of TI C2000 series 280049 chip [Copy link]

When the 280049 chip uses TI's library function, the register settings do not change after SPIA initialization, all are 0. At this time, you need to enable SPIA or SPIB. This problem has troubled me for a long time. Finally, I compared the two projects and found that

SysCtl_enablePeripheral(SYSCTL_PERIPH_CLK_SPIB);
This should be changed to SPIA, and then there will be no problem with initialization. I have to say that this kind of thing is really a pitfall

Jacktang

The initialization method given in the example is to initialize all 4 pins as asynchronous inputs and turn on the internal pull-up.
Whether in master mode or slave mode, there should be several pins that are output pins. Why are they all initialized as inputs?
Is it a loopback requirement or is there another reason?

It is not a loopback requirement. Even if it is configured as input mode, when the MUX is configured as SPI peripheral mode, it will automatically switch to peripheral mode, regardless of the GPIO input and output configuration.

Jacktang

You only need to configure the special function pins. You don’t need to consider input and output like GPIO.