24.6.1 TXxSTA
Transmit Status and Control Register
| Name: | TXxSTA |
| Offset: | 0x011E |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| CSRC | TX9 | TXEN | SYNC | SENDB | BRGH | TRMT | TX9D | ||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
Bit 7 – CSRC Clock Source Select
| Value | Name | Description |
|---|---|---|
| 1 | SYNC = 1 |
Host mode (clock generated internally from BRG) |
| 0 | SYNC = 1 |
Client mode (clock from external source) |
| X | SYNC = 0 |
Don’t care |
Bit 6 – TX9 9-Bit Transmit Enable
| Value | Description |
|---|---|
| 1 | Selects 9-bit transmission |
| 0 | Selects 8-bit transmission |
Bit 5 – TXEN Transmit Enable
Enables transmitter(1)
| Value | Description |
|---|---|
| 1 | Transmit enabled |
| 0 | Transmit disabled |
Bit 4 – SYNC EUSART Mode Select
| Value | Description |
|---|---|
| 1 | Synchronous mode |
| 0 | Asynchronous mode |
Bit 3 – SENDB Send Break Character
| Value | Name | Description |
|---|---|---|
| 1 | SYNC = 0 |
Send Sync Break on next transmission (cleared by hardware upon completion) |
| 0 | SYNC = 0 |
Sync Break transmission disabled or completed |
| X | SYNC = 1 |
Don’t care |
Bit 2 – BRGH High Baud Rate Select
| Value | Name | Description |
|---|---|---|
| 1 | SYNC = 0 |
High speed,
if BRG16 = 1, baud rate is baudclk/4; else
baudclk/16 |
| 0 | SYNC = 0 |
Low speed |
| X | SYNC = 1 |
Don’t care |
Bit 1 – TRMT Transmit Shift Register (TSR) Status
| Value | Description |
|---|---|
| 1 | TSR is empty |
| 0 | TSR is not empty |
Bit 0 – TX9D Ninth Bit of Transmit Data
Can be address/data bit or a parity bit.