HX712

AVIA SEMICONDUCTOR

8

Reference Driver (Assembly)

/*-------------------------------------------------------------------

Call from ASM:

LCALL

ReaAD

Call from C:

extern unsigned long ReadAD(void);

.

.

unsigned long data;

data=ReadAD();

.

.

----------------------------------------------------------------------*/

PUBLIC

ReadAD

HX712ROM

segment

code

rseg

HX712ROM

sbit

ADDO = P1.5;

sbit

ADSK = P0.0;

/*--------------------------------------------------

OUT:

R4, R5, R6, R7

R7=>LSB

---------------------------------------------------*/

ReadAD:

CLR

ADSK

//AD Enable（PD_SCK set low）

SETB

ADDO

//Enable 51CPU I/0

JB

ADDO,$

//AD conversion completed?

MOV

R4,#24

ShiftOut:

SETB

ADSK

//PD_SCK set high（positive pulse）

NOP

CLR

ADSK

//PD_SCK set low

MOV

C,ADDO

//read on bit

XCH

A,R7

//move data

RLC

A

XCH

A,R7

XCH

A,R6

RLC

A

XCH

A,R6

XCH

A,R5

RLC

A

XCH

A,R5

DJNZ

R4,ShiftOut

//moved 24BIT?

SETB

ADSK

NOP

CLR

ADSK

RET

END