SPRUJ53B April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
The SCI/LIN module can be put in either local or global low-power mode. Global low-power mode is asserted by the system and is not controlled by the SCI/LIN module. During global low-power mode, all clocks to the SCI/LIN are turned off so the module is completely inactive. If global low-power mode is requested while the receiver is receiving data, then the SCI/LIN completes the current reception and then enters the low-power mode, that is, module enters low-power mode only when Busy bit (SCIFLR.3) is cleared.
The LIN module can enter low-power mode either when there was no activity on the LINRX pin for more than 4 seconds (this can be either a constant recessive or dominant level) or when a Sleep Command frame was received. Once the Timeout flag (SCIFLR.4) was set or once a Sleep Command was received, the POWERDOWN bit (SCIGCR2.0) must be set by the application software to make the module enter local low-power mode. A wakeup signal terminates the sleep mode of the LIN bus.
Enabling Local Low-Power Mode During Receive and Transmit
If the wakeup interrupt is enabled and low-power mode is requested while the receiver is receiving data, then the SCI/LIN immediately generates a wakeup interrupt to clear the power-down bit. Thus, the SCI/LIN is prevented from entering low-power mode and completes the current reception. Otherwise, if the wakeup interrupt is disabled, the SCI/LIN completes the current reception and then enters the low-power mode.