AN1212 Freescale Semiconductor / Motorola, AN1212 Datasheet - Page 37

• Manufacturer Part Number: AN1212
• Description: J1850 Multiplex Bus Communication Using the MC68HC705C8 and the SC371016 J1850 Communications Interface (JCI)
• Manufacturer: Freescale Semiconductor / Motorola

031F
0321
0323
0324
0326
0328
032B
032D
0330
0333
0336
0339
033B
033C
033D
0340
0343
0345
0347
0349
034B
0360
0360
0362
0364
0366
MOTOROLA
A104
2708
5C
A124
2703
CC0340
EE43
CD01E1
0E3110
0D310D
CD01E1
B632
F7
5C
CC0330
CD027B
B633
B730
B635
B732
80
B630
B733
B632
B735
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
getmsg:
rxdata:
dump:
finish:
************************************************************************
*
*
*
************************************************************************
J1850 Multiplex Bus Communication Using the MC68HC705C8
and the SC371016 J1850 Communications Interface (JCI)
Freescale Semiconductor, Inc.
For More Information On This Product,
cmp
beq
incx
cmp
beq
jmp
ldx
jsr
brset rfifoa,status,finish
brclr rfifob,status,finish
jsr
lda
sta
incx
jmp
jst
lda
sta
lda
sta
rti
org
lda
sta
lda
sta
#id3
getmsg
#id4
getmsg
dump
msgl,x
TRANSFER
TRANSFER
data
,x
rxdata
RXFLUSH
cmdtemp
command
datatemp
data
timer
command
cmdtemp
data
datatemp
Go to: www.freescale.com
Timer Interrupt Service Routine
;Compare target i.d. with next message
;buffer i.d., if match, get message
;Increment X-Register
;Compare target i.d. with next message
;buffer i.d., if match, get message
;Not interested in this message
;Load pointer to corresponding message RAM
;buffer into X-Register
;Call TRANSFER subroutine, retrieving
;Status and source i.d. data byte
;Call TRANSFER subroutine, retrieving
;Status and data bytes
;Load received data into acc., then store
;it in next location in message buffer
;Increment X-Register
;Loop back to "rxdata" to check for
;another data byte
;Flush current Rx FIFO
;Retrieve command byte and
;store in command byte location
;Retrieve data byte and
;store in data byte location
;Return from interrupt
;Store current command byte in
;temporary storage location
;Store current data byte in
;temporary storage location
;Was previous byte "last byte"
;If so, don’t load any data
;Again, if no valid data,
;end routine
Code Listings
AN1212/D
37
*
*
*