Cirrus-logic AN118 Manual do Utilizador descarregar pdf (Página 29)

AN118

AN118REV2 29

;****************************************************************

;* Routine - RXSER

;* Input - none

;* Output - Byte received is placed in R7

;* Description - This subroutine receives 1 byte from converter

;* via UART. It uses the RS-232 serial protocol to transmit

;* one byte from a PC/UART system to the 8051.

;****************************************************************

; The function prototype is: char RXSER(void);

$DEBUG

USING 0 ; Use register bank 0

TCOD SEGMENT CODE ; Define ROUT as a segment of code

PUBLIC RXSER ; Make subroutine global

RSEG TCOD ; Make code relocatable

RXSER:

JNB SCON.0,$ ; Poll RI

MOV R7,SBUF ; Place received byte in R7

CLR SCON.0 ; Reset RI bit

RET

END

1 2 ... 24 25 26 27 28 29 30 31 32

Sem comentários

Cirrus-logic AN118 Manual do Utilizador Página 29