SPRUIW9C October 2021 – March 2024 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
Up to twelve independent peripheral signals are multiplexed on a single GPIO-enabled pin in addition to the CPU-controlled I/O capability. Each pin output can be controlled by either a peripheral or one of the two CPU masters.
There are up to 8 possible I/O ports:
The analog signals on this device are multiplexed with digital inputs and outputs. Some of these analog IO (AIO) pins do not have digital output capability. Others of these pins are analog pins capable of full digital input and output capability (AGPIO). Analog pins with AIO (digital input only) capability contain "AIO" signals in the Pin Attributes table of the device data sheet. Analog pins with full input and output capability (AGPIO pins) contain "GPIO" signals in the Pin Attributes table of the device data sheet. AGPIO pins also have pin names with both analog signals and GPIO in the name.
Figure 10-1 shows the GPIO logic for a single pin.
There are two key features to note in Figure 10-1. The first is that the input and output paths are entirely separate, connecting only at the pin. The second is that peripheral muxing takes place far from the pin. As a result, for both CPUs and CLAs to read the physical state of the pin independent of CPU mastering and peripheral muxing is possible. Likewise, external interrupts can be generated from peripheral activity. All pin options such as input qualification and open-drain output are valid for all masters and peripherals. However, the peripheral muxing, CPU muxing, and pin options can only be configured by CPU1. Table 10-1 provides details of GPIO registers accessible by different masters.
JTAG uses a different signal path that does not support inversion or qualification.
GPIO18/X2 and GPIO19/X1 have different timings due to the load placed on them by the oscillator circuit. For information on using GPIO18/X2 and GPIO19/X1 as GPIOs, see the data sheet and the Clocking section of this document.
If digital signals with sharp edges (high dv/dt) are connected to the AIOs or AGPIOs, cross-talk can occur with adjacent analog signals. Therefore, limit the edge rate of signals connected to AIOs or AGPIOs if adjacent channels are being used for analog functions.
Register Type | Function | CPU | CLA | DMA | HIC | Comments |
---|---|---|---|---|---|---|
GPIO_CTRL | Peripheral muxing, Pull Control ,etc. | Yes | No | No | No | - |
GPIO_DATA | GPIODAT, SET, CLEAR, TOGGLE, and pin status, etc. | Yes | Yes | No | No | Based on GPxCSEL configuration. |
GPIO_DATA_READ | Read back of GPIODAT register | Yes | Yes | No | Yes | - |