Channel 0 transmit control register
| ST | Start or Stop Transmission Command |
| TCW | Transmit Channel Weight |
| OSF | Operate on Second Packet |
| TSE | TCP Segmentation Enabled |
| IPBL | Ignore PBL Requirement |
| TXPBL | Transmit Programmable Burst Length |
| TQOS | Transmit QOS |
| EDSE | Enhanced Descriptor Enable |