SPRUIN7C March 2020 – March 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
The device supports an external clock source (XTAL), which can be used as the main system and CAN bit clock source. Frequency limits and timing requirements can be found in the TMS320F28002x Real-Time Microcontrollers Data Sheet. External clock sources use the X1/GPIO19 and X2/GPIO18 pins. After power-up, the X1 and X2 pin functionality can be enabled by following the procedure in Section 3.7.6.
Three types of external clock sources are supported:
XTALCR Bit (1) | Operating Mode | GPIO19 Available on X1? | GPIO18 Available on X2? | |
---|---|---|---|---|
OSCOFF | SE | |||
0 | 0 | Crystal Mode: Quartz crystal connected to X1/X2 | No | No |
0 | 1 | Single-Ended Mode: External clock on X1 | No | Yes |
1 | 0 | Oscillator off | Yes | Yes |
1 | 1 | Single-Ended Mode: External clock on X1(2) | No | Yes |