PIC16F870_13 Datasheet, PDF (69/172 Pages) Microchip Technology – 28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

PIC16F870/871
When setting up an Asynchronous Reception, follow
these steps:
1. Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH (Section 9.1).
2. Enable the asynchronous serial port by clearing
bit SYNC and setting bit SPEN.
3. If interrupts are desired, then set enable bit
RCIE.
4. If 9-bit reception is desired, then set bit RX9.
5. Enable the reception by setting bit CREN.
6. Flag bit RCIF will be set when reception is com-
plete and an interrupt will be generated if enable
bit RCIE is set.
7. Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
8. Read the 8-bit received data by reading the
RCREG register.
9. If any error occurred, clear the error by clearing
enable bit CREN.
10. If using interrupts, ensure that GIE and PEIE
(bits 7 and 6) of the INTCON register are set.
TABLE 9-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
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 _{-000 0000 -000 0000}
18h
RCSTA SPEN RX9 SREN CREN — FERR OERR RX9D _{0000 -00x 0000 -00x}
1Ah
RCREG USART Receive 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 locations read as '0'. Shaded cells are not used for asynchronous reception.
Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear.
 2000-2013 Microchip Technology Inc.
DS30569C-page 69