SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
This section provides description of the registers used for the EDMA wakeup interrupt functionality, including the EDMA_WAKE_INT IRQ status and enable fields. The EDMA Wakeup Interrupt allows incoming EDMA events to be latched and an interrupt sent to the DSP (if enabled). This interrupt is generated in the DSP_SYSTEM as an single "OR-ed" output of all external DMA requests latched in DSP subsystem. This output is further synchronized to DSP_FCLK and mapped as the EDMA_WAKE_INT event to the DSP_IRQ_31 input of the C66x DSP CorePac DSP_INTC. The C66x CPU is expected to service the interrupt by triggering the corresponding EDMA channel manually, or by servicing the request via normal reads and writes (instead of using the EDMA). This functionality is required since the EDMA is not capable of following the smart wakeup protocol.
The DSP_SYS_DMAWAKEEN0 / DSP_SYS_DMAWAKEEN1 registers are used for enabling the assertion of the 'Mwakeup' asynchronous wakeup request to the device PRCM upon DMA requests reception. The interrupt functionality of the registers: DSP_SYS_EDMAWAKE0_x covered in this subsection is specifically for generating an wake interrupt to the DSP. In most cases, the enable mask for the two sets of registers should be set to the same value.
The EDMAWAKE0 registers corresponding to the EDMA Events 19 thru 0 (msbit to lsbit) are as follows:
Following functional descriptions are valid for the above registers :
A DSP_SYS_EDMAWAKE0_IRQSTATUS_RAW bit is set even if the corresponding event is NOT enabled in the DSP_SYS_EDMAWAKE0_IRQENABLE_SET[19:0].