PIC16F870_13 Datasheet, PDF (73/172 Pages) Microchip Technology – 28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

PIC16F870/871
TABLE 9-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
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, INTCON GIE
10Bh,18Bh
0Ch
PIR1
PSPIF⁽¹⁾
PEIE
ADIF
T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u
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.
FIGURE 9-9:
SYNCHRONOUS TRANSMISSION
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
RC7/RX/DT pin
bit 0
bit 1
bit 2
bit 7
bit 0
bit 1
bit 7
RC6/TX/CK pin
Word 1
Word 2
Write to
TXREG reg
TXIF bit
(Interrupt Flag)
Write Word1
Write Word2
TRMT bit
'1'
'1'
TXEN bit
Note: Sync Master mode; SPBRG = 0. Continuous transmission of two 8-bit words.
FIGURE 9-10:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RC7/RX/DT pin
bit0
bit1
bit2
bit6
bit7
RC6/TX/CK pin
Write to
TXREG Reg
TXIF bit
TRMT bit
TXEN bit
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DS30569C-page 73