30.6.1 TXxSTA
Transmit Status and Control Register
Name: | TXxSTA |
Offset: | 0x0611,0x061B |
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.