SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
Figure 12-273 and Table 12-250 show a task issuance sequence.
Step | Description |
---|---|
1 | Find an empty transfer request slot by reading the MMCSD0_CQ_TASK_DOOR_BELL register. An empty transfer request slot has its respective bit cleared to '0' in the MMCSD0_CQ_TASK_DOOR_BELL register. |
2 | Build a Task Descriptor at the 1st entry of the empty slot. Task Descriptor field values:
|
3 | Build a Transfer Descriptor at the 2nd entry of the empty slot. Transfer Descriptor field values:
|
4 | If more than one transfer is requested, repeat step 1-3 for all needed transfers. |
5 | Set MMCSD0_CQ_TASK_DOOR_BELL register to indicate to the CQE that one or more transfer requests are ready to be sent to the attached device. Host software shall only write a '1' to the bit position that corresponds to new tasks; all other bit positions within MMCSD0_CQ_TASK_DOOR_BELL register should be written with a '0', which indicates no change to their current values. |