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

1.；接收一个字符，C=0接收正确，C＝1接收出错，容错次数为3

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

recchar://接收字符

MOV.B#3,ERRCNT

RECCHAR1:

clr.bicflag1

MOV.B#8,CNTREG

CLR.BTRDATA

MOV.W#40000,DELAYCNT

RECC_WAIT:

BIT.B#ICSAM//判断对卡还是对ESAM操作

JNZRECC_IC

bit.b#samio,&pinb//对SAM操作

jzRECC_WAITSAM05

JMPRECC_DEL

RECC_WAITSAM05:

call#delay05etu

bit.b#samio,&pinb

JZRECC_BEGIN

JMPRECC_DEL

RECC_IC:

BIT.B#ICIO,&PINA//判起始位，不超过40000个CLK

JZRECC_WAITIC05

JMPRECC_DEL

RECC_WAITIC05:

CALL#DELAY05ETU

BIT.B#ICIO,&PINA

JZRECC_BEGIN

RECC_DEL:

DEC.WDELAYCNT

JNZRECC_WAIT

BIS.B#C,SR//超时，置C=1

RET

RECC_BEGIN:

call#reconebyte//

BIT.B#ICXOR

JNZRECC_CMP1

BIT.B#MXOR

JZRECC_OK

JMPRECC_CMPERR

RECC_CMP1:

BIT.B#MXOR//MXOR=1?

JZRECC_CMPERR//=0,ERR

RECC_OK:

call#delay1etu

clrc

ret

RECC_CMPERR:

BIT.B#ICSAM

JNZRECC_IC2

BIS.B#SAMIO,&PDIRB

BIC.B#SAMIO,&POUTB

CALL#DELAY1ETU

BIS.B#SAMIO,&POUTB

JMPRECC_AGAIN

RECC_IC2:

BIS.B#ICIO,&PDIRA

BIC.B#ICIO,&POUTA

CALL#DELAY1ETU

BIS.B#ICIO,&POUTA

RECC_AGAIN:

CALL#DELAY1ETU

DEC.BERRCNT

CMP.B#0,ERRCNT

JNZRECCHAR1

SETC

RET

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

2.；开始接收数据位,并计算校验位

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

reconebyte:

BIT.B#ICSAM

JNZROB_IC

rob_next:

call#delay1etu

bit.b#samio,&pinb

jzrob_1

xor.b#80h,icflag1

setc

jmprob_2

rob_1:

clrc

rob_2:

rrc.btrdata

sub.b#1,cntreg

jnzrob_next

call#delay1etu

bit.b#samio,&pinb

jzrob_out

bis.b#icxor

JMPROB_OUT

ROB_IC:

call#delay1etu

bit.b#ICio,&pinA

jzrob_IC1

xor.b#80h,icflag1

setc

jmprob_IC2

rob_IC1:

clrc

rob_IC2:

rrc.btrdata

sub.b#1,cntreg

jnzROB_IC

call#delay1etu

bit.b#ICio,&pinA

jzrob_out

bis.b#icxor

rob_out:

call#delay05etu

ret