TMS320F28P550SG: Pin description

Hello Rannie,

Great question about the multiplexed pin functionality on the TMS320F28P550SG!

Short Answer: No, you cannot use both A16 and B16 simultaneously on the same physical pin.

Explanation:

Looking at the pin attributes table you've shared, A16, B16, and C16 are all multiplexed to the same physical pin (GPIO28). This means:

1. Only ONE function can be active at a time on this physical pin

2. The MUX POSITION setting determines which function is currently active:

   • If you configure it as A16 (ADC-A Input 16), only ADC-A can read from this pin
   • If you configure it as B16 (ADC-B Input 16), only ADC-B can read from this pin
   • If you configure it as C16 (ADC-C Input 16), only ADC-C can read from this pin
   • You can also configure it as GPIO28 for general-purpose I/O

3. The pin mux configuration is controlled by registers (typically GPxGMUX and GPxMUX registers) which select one of the available functions

What You CAN Do:

If you need to read the same analog signal with both ADC-A and ADC-B:

• Route the external signal to two separate pins - one configured as A16 and another configured as B16 (on different physical pins)
• This allows simultaneous sampling by both ADCs

Register Configuration:

The pin function is selected through the GPIO mux registers, and only one configuration can be active. You cannot have multiple ADC inputs reading the same physical pin simultaneously.

Let me know if you need clarification on pin muxing configuration or alternative approaches for your application! I would recommend playing around with the pinmux tool: https://dev.ti.com/sysconfig/#/config/?args=--device%20TMS320F28P550SG%20--package%20128PDT%20--variant%20TMS320F28P550SG9

Best Regards,

Zackary Fleenor