SPRSP61C October 2021 – December 2023 TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038C-Q1 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
PRODMIX
Some GPIOs on this device are multiplexed with analog pins. These are also referred to as AGPIOs. Unlike AIOs, AGPIOs have full input and output capability. This device has two GPIOs (GPIO20, GPIO21) that offer this feature on the 100-Pin PZ and 80-Pin PN packages.
100-Pin PZ: On this package, there are dedicated pins for B5 (pin 32) and B11 (pin 30) which respectively also have AIO252 and AIO251 functionality. In addition, GPIO20 (pin 48) and GPIO21 (pin 49) are also available as B5 and B11 respectively. Since B5 and B11 are dedicated pins on this package, it is recommended to use them instead of the ones on GPIO20/21.
80-Pin PN: On this package, GPIO20 (pin 33) and GPIO21 (pin 34) are also available as B5 and B11 respectively. There are no dedicated pin for B5 and B11.
By default the AGPIOs are not connected and have to be configured. Table 5-7 truth table shows how to configure the AGPIOs using B5 (pin 32) and GPIO20 (pin 48) on the 100-Pin PZ as an example.
AGPIOCTRLA.bit.GPIO20 | GPAAMSEL.bit.GPIO20 | GPHAMSEL.bit.GPIO252 | B5 CONNECTED TO | GPIO20 CONNECTED TO | ||||
---|---|---|---|---|---|---|---|---|
ADC | GPIO20 | AIO252 | ADC | GPIO20 | AIO252 | |||
0 | 0 | 1 | Yes | - | - | - | Yes | - |
0 | 1 | 1 | Yes | - | - | - | - | - |
1 | 0 | 1 | Yes | - | - | - | Yes | - |
1 | 1 | 1 | - | - | - | Yes | - | - |
0 | 0 | 0 | Yes | - | Yes | - | Yes | - |
0 | 1 | 0 | Yes | - | Yes | - | - | - |
1 | 0 | 0 | Yes | - | Yes | - | Yes | - |
1 | 1 | 0 | - | - | Yes | Yes | - | - |
If digital signals with sharp edges (high dv/dt) are connected to the AGPIOs, cross-talk can occur with adjacent analog signals. The user should therefore limit the edge rate of signals connected to AGPIOs if adjacent channels are being used for analog functions.