Zilog Z16C35 - Manual (Page 240)

Application Note
SCC in Binary Synchronous Communications
10-10
RECEIVE ROUTINE
RECEIVE A BLOCK OF MESSAGE
THE LAST CHARACTER SHOULD BE EOT (%04)
006C
GLOBAL
ENTRY
RECEIVE PROCEDURE
006C C828 LDB RL0,#428 !WAIT ON RECV.!
006C 3A86 OUTB WR0A+2,RL0
0070 FE23
0072 6000 LDB RL0,%A8
0074 00AB
0076 3A86 OUTB WR0A+2,RL0 !ENABLE WAIT 1ST CHAR,SP.COND. INT!
0078 FE23
007A 2101 LD Rl,#RR0A+16
007C FE31
007E 3Cl8 INB RL0,@R1 !READ STX CHARACTER!
0080 C8C9 LDB RL0,#%C9
0082 3AB6 OUTB WR0A+6,RL0 !Rx CRC ENABLE!
0084 FE27
0086 2103 LD R3,#RBUF
0088 5400
008A 3C18 READ: INB RL0,@R1 !READ MESSAGE!
008C 2E38 LDB @R3,RL0 !STORE CHARACTER IN RBUF!
008E AB30 DEC R3,#l
0090 0A08 CPB RL0,#%04 !IS IT END OF TRANSMISSION ?!
0092 0404
0094 EEFA JR NZ,READ
0096 3C18 INB RL0,@R1 !READ PAD1!
0098 3C18 INB RL0,@R1 !READ PAD2!
009A 3A84 INB RL0,RR0A+2 !READ CRC STATUS!
009C FE23
! PROCESS CRC ERROR IF ANY, AND GIVE ERROR RESET COMMAND IN WR0A!
009E C800 LDB RL0,#0
00A0 3A86 OUTB WR0A+6,RL0 !DISABLE RECEIVER!
00A2 FE27
00A4 9E08 RET
00A6 END RECEIVE
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