mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-08-15 00:29:02 +00:00
189 lines
3.5 KiB
ArmAsm
189 lines
3.5 KiB
ArmAsm
;;;
|
|
;;;
|
|
;;; rs232-asm.S
|
|
;;;
|
|
;;; PC-6001 Architecture depend RS-232C implementation,
|
|
;;; uses a bunch of BIOS functions.
|
|
;;;
|
|
;;; @author Takahide Matsutsuka <markn@markn.org>
|
|
;;;
|
|
;;; $Id: rs232-asm.S,v 1.3 2007/11/28 09:39:30 matsutsuka Exp $
|
|
;;;
|
|
|
|
;; definitions of PC-6001 BIOS routines
|
|
_rs232c_initialize = 0x19bf
|
|
_buffer_out = 0x2627
|
|
_char_input_sub = 0x2642
|
|
_count_buffer = 0x26a2
|
|
_rs232c_intr_vector = 0xfa04
|
|
_subcpu_handshake_out = 0x0e8f
|
|
LOG = 0
|
|
CTK = 0
|
|
;; export symbols
|
|
.globl _rs232_arch_writeb
|
|
.globl _rs232_arch_poll
|
|
.globl _rs232_arch_init
|
|
|
|
.area _CODE
|
|
|
|
.if LOG
|
|
_hex:
|
|
.ascii "0123456789ABCDEF"
|
|
.if CTK
|
|
.globl _cputc_arch_asm
|
|
.else
|
|
.globl _libputc_asm
|
|
.globl _screen_offset
|
|
.endif
|
|
_rs232_arch_putc: ; a = data
|
|
ld hl, #0
|
|
ld (#_screen_offset), hl
|
|
push af
|
|
srl a
|
|
srl a
|
|
srl a
|
|
srl a
|
|
call _rs232_arch_putc_next1
|
|
pop af
|
|
and a, #0x0f
|
|
_rs232_arch_putc_next1:
|
|
ld hl, #_hex
|
|
_rs232_arch_putc_loop:
|
|
or a
|
|
jr z, _rs232_arch_putc_next2
|
|
inc hl
|
|
dec a
|
|
jr _rs232_arch_putc_loop
|
|
_rs232_arch_putc_next2:
|
|
ld a, (hl)
|
|
.if CTK
|
|
call _cputc_arch_asm
|
|
.else
|
|
call _libputc_asm
|
|
.endif
|
|
ret
|
|
.endif
|
|
|
|
;; ---------------------------------
|
|
;; void rs232_writeb(u8_t c)
|
|
;; Stack; retl reth c
|
|
;; AF__D_HL____
|
|
;; return void
|
|
;; ---------------------------------
|
|
_rs232_arch_writeb:
|
|
ld hl, #2
|
|
add hl, sp
|
|
ld d, (hl)
|
|
.if LOG
|
|
push de
|
|
ld a, #0x77 ; 'w'
|
|
.if CTK
|
|
call _cputc_arch_asm
|
|
.else
|
|
call _libputc_asm
|
|
.endif
|
|
pop de
|
|
;; ld a, d
|
|
;; push de
|
|
;; call _rs232_arch_putc
|
|
;; pop de
|
|
.endif
|
|
_rs232_arch_writeb_loop:
|
|
in a, (#0x81)
|
|
and a, #0x01
|
|
cp #0x01 ; TxRDY? 0x01/0x81/0x85
|
|
jr nz, _rs232_arch_writeb_loop
|
|
ld a, d
|
|
out (#0x80), a
|
|
ret
|
|
|
|
;; RS-232C interrupt routine
|
|
;; receive a byte and put it into the buffer
|
|
_rs232_arch_intr:
|
|
push bc
|
|
push af
|
|
push de
|
|
push hl
|
|
in a, (#0x81)
|
|
and a, #0x02 ; RxRDY?
|
|
jr z, _rs232_arch_intr_next ; no input
|
|
in a, (#0x80)
|
|
ld e, a
|
|
ld a, #0x01
|
|
call _buffer_out ; buffer output A=bufno, e=data
|
|
_rs232_arch_intr_next:
|
|
ld a, #0x0c
|
|
call _subcpu_handshake_out ; sub CPU handshake output A
|
|
call _rs232_arch_bufchk
|
|
pop hl
|
|
pop de
|
|
pop af
|
|
pop bc
|
|
ei
|
|
ret
|
|
|
|
_rs232_arch_bufchk:
|
|
ld a, #0x01
|
|
call _count_buffer ; count buffer available bytes -> A
|
|
cp #0x02 ; A >= 2?
|
|
ld a, #0x37 ; Rx enable
|
|
jr nc, _rs232_arch_bufchk_next ; buffer available bytes >= 2
|
|
ld a, #0x33 ; Rx disable
|
|
_rs232_arch_bufchk_next:
|
|
out (#0x81),a ; buf available=0x37, buf full=0x33
|
|
ret
|
|
|
|
;; ---------------------------------
|
|
;; unsigned char rs232_arch_poll(unsigned char *stat);
|
|
;; Stack; retl reth statl stath
|
|
;; AFBCDEHL____
|
|
;; return input byte (*stat == 0 if no input)
|
|
;; ---------------------------------
|
|
_rs232_arch_poll:
|
|
ld hl, #2
|
|
add hl, sp
|
|
ld e, (hl)
|
|
inc hl
|
|
ld d, (hl)
|
|
ld a, #0x01
|
|
ld (de), a
|
|
di
|
|
call _char_input_sub ; read from buffer
|
|
ei
|
|
push af
|
|
call _rs232_arch_bufchk ; buffer check
|
|
pop af
|
|
jr nz, _rs232_arch_poll_ret
|
|
xor a ; we have no data in the buffer
|
|
ld (de), a
|
|
jr _rs232_arch_poll_ret2
|
|
_rs232_arch_poll_ret:
|
|
.if LOG
|
|
call _libputc_asm
|
|
;; call _rs232_arch_putc
|
|
.endif
|
|
_rs232_arch_poll_ret2:
|
|
pop af
|
|
ld l, a
|
|
ret
|
|
|
|
;; ---------------------------------
|
|
;; void rs232_init(unsigned long ubr);
|
|
;; Stack; retl reth ubr1 ubr2 ubr3 ubr4
|
|
;; AFB_DEHL____
|
|
;; return void
|
|
;; ---------------------------------
|
|
_rs232_arch_init:
|
|
ld hl, #_rs232_arch_intr
|
|
di
|
|
ld (#_rs232c_intr_vector), hl
|
|
ei
|
|
;; S2 S1 PE P L2 L1 B2 B1
|
|
;; 0 1 0 0 1 1 1 1
|
|
;; 8-N-1 64x clock
|
|
ld b, #0x4f
|
|
call _rs232c_initialize
|
|
ld a, #0x37
|
|
out (#0x81), a
|
|
ret
|