Datasheet

 2000-2013 Microchip Technology Inc. DS30569C-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 0000 -000
18h RCSTA SPEN
RX9 SREN CREN — FERR OERR RX9D
0000 -00x 0000 -00x
19h TXREG USART Transmit Register
0000 0000 0000 0000
8Ch PIE1
PSPIE
(1)
ADIE RCIE TXIE — CCP1IE TMR2IE TMR1IE
0000 -000 0000 -000
98h TXSTA CSRC TX9 TXEN SYNC
— BRGH TRMT TX9D
0000 -010 0000 -010
99h SPBRG Baud Rate Generator Register
0000 0000 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 Q3Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2 Q3Q4 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3Q4Q1Q2Q3 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' '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