
PIC16F62X
DS40300C-page 76
Preliminary
2003 Microchip Technology Inc.
FIGURE 12-7:
ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
TABLE 12-6:
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
all other
RESETS
0Ch
PIR1
EEIF
CMIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
ADEN
FERR
OERR
RX9D
0000 -00x
19h
TXREG
USART Transmit Register
0000 0000
8Ch
PIE1
EEIE
CMIE
RCIE
TXIE
—
CCP1IE
TMR2IE
TMR1IE
0000 -000
98h
TXSTA
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
99h
SPBRG
Baud Rate Generator Register
0000 0000
Legend: x = unknown, - = unimplemented locations read as '0'.
Shaded cells are not used for Asynchronous Transmission.
Transmit Shift Reg.
Write to TXREG
BRG output
(shift clock)
RB2/TX/CK (pin)
TXIF bit
(interrupt reg. flag)
TRMT bit
(Transmit shift
reg. empty flag)
WORD 1
WORD 2
WORD 1
WORD 2
START Bit
STOP Bit
START Bit
Transmit Shift Reg.
WORD 1
WORD 2
Bit 0
Bit 1
Bit 7/8
Bit 0
.
Note
1: This timing diagram shows two consecutive transmissions.