PIC17C75X
FIGURE F-10: TXSTA1 REGISTER (ADDRESS: 15h, BANK 0)
TXSTA2 REGISTER (ADDRESS: 15h, BANK 4)
R/W - 0 R/W - 0 R/W - 0 R/W - 0
CSRC TX9 TXEN SYNC
bit7
U - 0
—
U - 0
—
R - 1
TRMT
R/W - x
TX9D
R = Readable bit
W = Writable bit
-n = Value at POR reset
(x = unknown)
bit0
bit 7:
CSRC: Clock Source Select bit
Synchronous mode:
1 = Master Mode (Clock generated internally from BRG)
0 = Slave mode (Clock from external source)
Asynchronous mode:
Don’t care
bit 6:
bit 5:
TX9: 9-bit Transmit Select bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
TXEN: Transmit Enable bit
1 = Transmit enabled
0 = Transmit disabled
SREN/CREN overrides TXEN in SYNC mode
bit 4:
SYNC: USART Mode Select bit
(Synchronous/Asynchronous)
1 = Synchronous mode
0 = Asynchronous mode
bit 3-2: Unimplemented: Read as '0'
bit 1:
TRMT: Transmit Shift Register (TSR) Empty bit
1 = TSR empty
0 = TSR full
bit 0:
TX9D: 9th bit of transmit data (can be used to calculated the parity in software)
DS30264A-page 282
Preliminary
1997 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
