SPRUJC6A December 2024 – July 2025 AM2752-Q1 , AM2754-Q1
The Ring N Doorbell Register is written by software to increment or decrement the number of entries on a Ring. One or more entries as specified by the entry_cnt field can be added to a ring with a single write operation.
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| Instance Name | Physical Address |
|---|---|
| DMASS0_BCDMA_0 | 4BC0 1010h + formula |
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 |
| TDOWN_ACK | RESERVED | ||||||
| NA/W | NONE | ||||||
| 0h | 0h | ||||||
| 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
| RESERVED | |||||||
| NONE | |||||||
| 0h | |||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| RESERVED | |||||||
| NONE | |||||||
| 0h | |||||||
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| ENTRY_CNT | |||||||
| NA/W | |||||||
| 0h | |||||||
| Bit | Field | Type | Reset | Description |
|---|---|---|---|---|
| 31 | TDOWN_ACK | NA/W | 0h | This bit is set to 1 to ackowledge (and clear) the tdown_complete bit in the corresponding Ring N Occupancy Register. this bit is only valid on the reverse rings (rings consumed by the Host SW) Reset Source: rst_mod_g_rst_n |
| 30:8 | RESERVED | NONE | 0h | Reserved |
| 7:0 | ENTRY_CNT | NA/W | 0h | Signed number of entries by which to increment the ring occupancy. For normal Tx Ring operation, this value should be a positive number. This occ value for the ring is increased by this value each time the doorbell register is written (occ absolute value will increase or decrease based on the sign of the ENTRY_CNT). Reset Source: rst_mod_g_rst_n |