Cirrus-logic AN74 Bedienungsanleitung PDF herunterladen (Seite 12)

AN74

12 AN74Rev2

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

;* Routine - TOGGLE_SDO

;* Input - none

;* Output - none

;* Description - This routine reset the DRDY pin by toggling

;* SCLK 8 times after SDO falls.

; This routine polls SDO, waits for it to be asserted, then clears SDO

; for next conversion by pulsing SCLK eight times after SDO falls

; This functions prototype in C is: void toggle_sdo(void);

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

$DEBUG

USING 0 ; Use register bank 0

TCOD SEGMENT CODE ; Define Rout as a segment of code

PUBLIC TOGGLE_SDO ; Make subroutine public

RSEG TCOD ; Make code relocatable

TOGGLE_SDO:

MOV R1,#08 ; Setup counter

CLR P1.1 ; Clear SDI

JB P1.2,$ ; Poll SDO

loop:

SETB P1.3 ; Set SCLK

CLR P1.3 ; Clear SCLK

DJNZ R1,loop ; Decrement byte, repeat loop if not zero

RET ; Exit Subroutine

END

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Cirrus-logic AN74 Bedienungsanleitung Seite 12