5.4.61 Collision Detector Control 0 Register - Rev D
Important: When writing to this register, use a read-modify-write operation
to avoid accidental modifications to RESERVED fields. Failure to use a read-modify-write
operation may result in adverse operation and unexpected
results.
| Name: | CDCTL0 - Rev D |
| Address: | 0x0087 |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| CDEN | CCMFC[1:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | RO | R/W | R/W | R/W | |
| Reset | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
Bit 15 – CDEN Collision Detect Enable
When set, this bit enables the detection of collisions on the physical medium when transmitting.
| Value | Description |
|---|---|
0 |
Collision detection is disabled |
1 |
Collision detection is enabled (default) |
Bits 10:9 – CCMFC[1:0] Collision Counting and MAC Forwarding Control
When CDEN is ‘0’ this field configures how detected collisions are counted within the device and forwarded to the MAC through the MII or RMII.
This field has no effect when CDEN is ‘0’ as collision detection is disabled.
| Value | Description |
|---|---|
00 |
IEEE default: Collisions counted and forwarded to the MAC |
x1 |
OA default: Collisions counted and forwarded to the MAC when PLCA_Status ≠ OK Collisions neither counted nor forwarded to the MAC when PLCA_Status = OK |
10 |
Collisions counted and forwarded to the MAC when PLCA_Status ≠ OK Collisions counted but not forwarded to the MAC when PLCA_Status = OK |