SPRUJC6A December 2024 – July 2025 AM2752-Q1 , AM2754-Q1
Enet Port N Mac Backoff Test
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| Instance Name | Physical Address |
|---|---|
| CPSW0 | 0802 333Ch + formula |
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 |
| RESERVED | PACEVAL | RNDNUM | |||||
| NONE | R/W | R/W | |||||
| 0h | 0h | 0h | |||||
| 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
| RNDNUM | |||||||
| R/W | |||||||
| 0h | |||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 |
| COLL_COUNT | RESERVED | TX_BACKOFF | |||||
| R | NONE | R | |||||
| 0h | 0h | 0h | |||||
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| TX_BACKOFF | |||||||
| R | |||||||
| 0h | |||||||
| Bit | Field | Type | Reset | Description |
|---|---|---|---|---|
| 31 | RESERVED | NONE | 0h | Reserved |
| 30:26 | PACEVAL | R/W | 0h | Pacing Current Value. A non-zero value in this field indicates that transmit pacing is active. A transmit frame collision or deferral causes paceval to loaded with decimal 31, good frame transmissions (with no collisions or deferrals) cause paceval to be decremented down to zero. When paceval is nonzero, the transmitter delays 4 IPGs between new frame transmissions after each successfully transmitted frame that had no deferrals or collisions. Transmit pacing helps reduce 'capture' effects improving overall network bandwidth. |
| 25:16 | RNDNUM | R/W | 0h | Backoff Random Number Generator. This field allows the Backoff Random Number Generator to be read (or written in test mode only). This field can be written only when CPSW_PN_MAC_CONTROL_REG_k[2] MTEST bit has previously been set. Reading this field returns the generator's current value. The value is reset to zero and begins counting on the clock after the de-assertion of reset. |
| 15:12 | COLL_COUNT | R | 0h | Collision Count. |
| 11:10 | RESERVED | NONE | 0h | Reserved |
| 9:0 | TX_BACKOFF | R | 0h | Backoff Count. This field allows the current value of the backoff counter to be observed for test purposes. This field is loaded automatically according to the backoff algorithm, and is decremented by one for each slot time after the collision. |