Zilog Z16C35 User Manual
Page 296
Application Note
Technical Considerations When Implementing LocalTalk Link Access Protocol
14-8
LISTING 4
1306
1307 ;****************************************
1308
;ctc1 timer int handler
1309 ;****************************************
00000509
1310 ctc1int:
1311
;ctc1 is programmed in counter mode.
1312
;external trigger edges is provided by
1313
;/trxc pin at intervals of 4.3 usec.
1314
;bit1 of timflg is set when count is terminated.
00000509 f5
1315
push
af
0000050a c5
1316
push
bc
0000050b e5
1317
push
hl
1318
;** update the timing flag **
0000050c 21Wwww
1319
ld
hl,timflg
0000050f 7e
1320
ld
a,(hl)
;get recent timflg
00000510 cbcf
1321
set
1,a
;bit1=1 after count is over
00000512 77
1322
ld
(hl),a
;update the timflg
00000513 e1
1323
pop
hl
00000514 c1
1324
pop
bc
00000515 f1
1325
pop
af
00000516 fb
1326
ei
00000517 ed4d
1327
reti
1328
1329
1330
1331 ;**********************************
1332
;interrupt vector table for the scc
1333 ;**********************************
1334
;the status of the interrupt source will affect
1335
;the interrupt vector. The interrupt handler’s
1336
;address are set in a block, as below.
00000a00
1337
org
sdlc + 0a00h
00000a00
1338 sccvect:
1339 if
scc_a
00000a00
1340
.block
8
;reserve vector for other ch
1341 endif
00000a08 R000+03e9,
1342
dw
txint
;tx int
00000a0a R000+04c8,
1343
dw
ext_stat
;ext/stat int
00000a0c R000+0433,
1344
dw
recint
;rx char int
00000a0e R000+0454,
1345
dw
spcond
;sp rec cond int
1346
1347 if
not
scc_a
00000a10
1348
.block
8
;reserve vector for other ch
1349 endif
1350
00000a18
1351 temp:
.block
1
1352
1353
1354 ;**********************************
1355
;interrupt vector table for the ctc
1356 ;**********************************
00000ad0
1357 org 0ad0h
00000ad0 R000+04d8,
1358
dw
ctc0int
;reserved for ctc0 int routine
00000ad2
1359 org 0ad2h
00000ad2 R000+0509,
1360
dw
ctc1int
;reserved for ctc1 int routine
1361
1362 ;************************
1363
;receive buffer area
1364 ;************************
Page 290 of 316
UM011002-0808