
2003 Microchip Technology Inc.
DS30569B-page 73
PIC16F870/871
TABLE 9-8:
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
FIGURE 9-9:
SYNCHRONOUS TRANSMISSION
FIGURE 9-10:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on
all other
RESETS
0Bh, 8Bh,
10Bh,18Bh
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
R0IF
0000 000x
0000 000u
0Ch
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
—
CCP1IF
TMR2IF
TMR1IF
0000 -000
18h
RCSTA
SPEN
RX9
SREN
CREN
—
FERR
OERR
RX9D
0000 -00x
19h
TXREG
USART Transmit Register
0000 0000
8Ch
PIE1
PSPIE(1)
ADIE
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, read as '0'. Shaded cells are not used for synchronous master transmission.
Note
1:
Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear.
bit 0
bit 1
bit 7
Word 1
Q1Q2 Q3Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2 Q3Q4
Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4
bit 2
bit 0
bit 1
bit 7
RC7/RX/DT pin
RC6/TX/CK pin
Write to
TXREG reg
TXIF bit
(Interrupt Flag)
TXEN bit
'1'
Word 2
TRMT bit
Write Word1
Write Word2
Note: Sync Master mode; SPBRG = 0. Continuous transmission of two 8-bit words.
RC7/RX/DT pin
RC6/TX/CK pin
Write to
TXREG Reg
TXIF bit
TRMT bit
bit0
bit1
bit2
bit6
bit7
TXEN bit