Zilog Z16C35 Manuale Utente Scaricare il pdf (Pagina 291)

14-11

0000027c d3e8 660 out (scc_cont),a

0000027e 3e6b 661 ld a,01101011b ;sdlc crc,

662 ;txcrc enable,

663 ;reset rts

00000280 d3e8 664 out (scc_cont),a

665

666 ;

667 ;**start counting out 2 ﬂag character times **

668 ;

669 ;count 16 bit times

670 ;from the rs-422 enable

671 ;for 2 ﬂags.

672 ;btdelay=subr delay+ctc1int+polling=8bits

673 ;16 bit times-btdelay=16-8=08h

674 ;

00000282 0e08 675 ld c,08h

00000284 cdWwww 676 call bittime ;bittime delay

677 ;is stored in reg.c

678 ;and bit1 of timﬂg

679 ;will indicate

680 ;count termination.

681

00000287682 l6: ;timer ﬂag

00000287 3aWwww 683 ld a,(timﬂg) ;

0000028a cb4f 684 bit 1,a ;if bit1=1 then

685 ;count terminated

0000028c 28f9 686 jr z,l6 ;

0000028e cb8f 687 res 1,a ;reset timﬂg bit1

00000290 32Wwww 688 ld (timﬂg),a ;update timﬂg

689 ;

00000293 3e03 690 ld a,03h ;

00000295 d3e5 691 out (ctc1_cont),a ;disable int,

692 ;software reset

693 ;to kill the counter1

00000297 0602 694 ld b,02h ;2+1 bytes to transmitted

00000299 21Wwww 695 ld hl,txlapenq ;point to txlapenq buffer

696 ;send 1st byte

0000029c 7e 697 ld a,(hl) ;

0000029d d3e9 698 out (scc_data),a ;and send it

0000029f 23 699 inc hl ;point to the next byte

700 ;

000002a0 3ec0 701 ld a,0c0h ;reset eom latch command

000002a2 d3e8 702 out (scc_cont),a

703 ;

000002a4 f3 704 di ;disable all int

000002a5 3e0a 705 ld a,0ah ;select WR10

000002a7 d3e8 706 out (scc_cont),a

707 ;idle with 1’s

708 ;at the end of the frame

000002a9 3ee8 709 ld a,11101000b

000002ab d3e8 710 out (scc_cont),a

711 ;

000002ad 3e00 712 txq2: ld a,00h

000002af d3e8 713 out (scc_cont),a ;rr0

000002b1 dbe8 714 in a,(scc_cont) ;read rr0

000002b3 cb57 715 bit 2,a ;read tx buffer empty

000002b5 28f6 716 jr z,txq2 ;loop if zero

000002b7717 txq1:

000002b7 7e 718 ld a,(hl) ;

000002b8 d3e9 719 out (scc_data),a ;and send it

000002ba 23 720 inc hl ;point to the next byte

721

Application Note

Technical Considerations When Implementing LocalTalk Link Access Protocol

Page 285 of 316

UM011002-0808

1 2 ... 286 287 288 289 290 291 292 293 294 295 296 ... 321 322

Commenti su questo manuale

Nessun commento

Zilog Z16C35 Manuale Utente Pagina 291

Commenti su questo manuale

Prodotti e manuali riguardandi Sensori Zilog Z16C35