Microchip Technology MA180025 Data Sheet
PIC18F87J90 FAMILY
DS39933D-page 276
2010 Microchip Technology Inc.
REGISTER 20-1:
TXSTA2: AUSART TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
U-0
R/W-0
R-1
R/W-0
CSRC
TX9
TXEN
(1)
SYNC
—
BRGH
TRMT
TX9D
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1
Asynchronous mode:
Don’t care.
Synchronous mode:
1
= Master mode (clock generated internally from BRG)
0
= Slave mode (clock from external source)
bit 6
TX9: 9-Bit Transmit Enable bit
1
= Selects 9-bit transmission
0
= Selects 8-bit transmission
bit 5
TXEN: Transmit Enable bit
(1)
1
= Transmit enabled
0
= Transmit disabled
bit 4
SYNC: AUSART Mode Select bit
1
= Synchronous mode
0
= Asynchronous mode
bit 3
Unimplemented: Read as ‘0’
bit 2
BRGH: High Baud Rate Select bit
Asynchronous mode:
1
Asynchronous mode:
1
= High speed
0
= Low speed
Synchronous mode:
Unused in this mode.
Unused in this mode.
bit 1
TRMT: Transmit Shift Register Status bit
1
= TSR empty
0
= TSR full
bit 0
TX9D: 9th bit of Transmit Data
Can be address/data bit or a parity bit.
Can be address/data bit or a parity bit.
Note 1:
SREN/CREN overrides TXEN in Sync mode.