jw002.asm

一款MP3 Player Firmware 的原代码,非常有参考价值

	lcall	pushbutton
	mov	c, pb_recv_4
	mov	r0, #pb_state+9
	mov	r1, #pb_config+9
	lcall	pushbutton
	mov	pb_scan_state, #2
	setb	pb_xmit_1
	setb	pb_xmit_2
	clr	pb_xmit_3
	pop	reg1
	pop	reg0
	pop	acc
	pop	psw
	reti
pb_row_3:
	mov	c, pb_recv_1
	mov	r0, #pb_state+3
	mov	r1, #pb_config+3
	lcall	pushbutton
	mov	c, pb_recv_2
	mov	r0, #pb_state+2
	mov	r1, #pb_config+2
	lcall	pushbutton
	mov	c, pb_recv_3
	mov	r0, #pb_state+7
	mov	r1, #pb_config+7
	lcall	pushbutton
	mov	c, pb_recv_4
	mov	r0, #pb_state+11
	mov	r1, #pb_config+11
	lcall	pushbutton
	mov	pb_scan_state, #0
	clr	pb_xmit_1
	setb	pb_xmit_2
	setb	pb_xmit_3
	pop	reg1
	pop	reg0
	pop	acc
	pop	psw
	reti



	;Let's be really paranoid, and only reset the watchdog if some
	;sanity checks are valid.  If any of these checks fail, something
	;has done horribly wrong and we must reboot.
	;Checks: uart and timer1 confired, stack pointer is legal
watchdog:
	mov	a, th1
	cjne	a, #baud_const, reboot
	mov	a, tmod
	cjne	a, #0x21, reboot
	mov	a, tcon
	anl	a, #01010000b
	cjne	a, #0x50, reboot
	mov	a, scon
	anl	a, #11110000b
	cjne	a, #0x50, reboot
	mov	a, pcon
	jnb	acc.7, reboot
	mov	a, sp
	add	a, #256 - stack
	jnc	reboot
	cpl	watchdog_pin
	ret


reboot:
	ljmp	location
retinow:
	reti



	.equ	event_dn, 0x10
	.equ	event_up, 0x20
	.equ	event_ar, 0x30


	;C = pushbutton state
	;r0 = ptr to pb_state
	;r1 = ptr to pb_config
pushbutton:
	jc	pb_up
pb_dn:			;the button is being pressed right now!
	mov	a, @r0
	jz	pb_dn_wait
	dec	a
	jnz	pb_ar
	mov	@r0, #2
	mov	a, r0
	add	a, #(event_dn - pb_state) & 255
	sjmp	emit_pb_event
pb_dn_wait:
	mov	@r0, #1
	ret
pb_ar:			;the button has been down for a while
	inc	@r0
	mov	a, @r1
	anl	a, #3
	add	a, #2
	movc	a, @a+pc	;grab auto-repeat threshold
	sjmp	pb_ar2
	.db	120, 90, 65, 43
pb_ar2:	clr	c
	subb	a, @r0
	jnc	pb_end		;did we hit the auto-repeat threshold?
	mov	a, @r1
	rr	a
	rr	a
	anl	a, #7
	add	a, #2
	movc	a, @a+pc	;grab auto-repeat speed
	sjmp	pb_ar3
	.db	40, 34, 29, 23, 18, 15, 12, 8
pb_ar3:	cpl	a
	inc	a
	add	a, @r0
	mov	@r0, a
	mov	a, r0
	add	a, #(event_ar - pb_state) & 255
	sjmp	emit_pb_event
pb_up:			;the button is not presssed
	mov	a, @r0
	jz	pb_end
	dec	a
	jz	pb_up_ignore
	mov	@r0, #0
	mov	a, r0
	add	a, #(event_up - pb_state) & 255
	sjmp	emit_pb_event
pb_up_ignore:
	mov	@r0, #0
pb_end:
	ret



emit_pb_event:
	mov	r0, a
	mov	a, pb_event_head
	inc	a
	cjne	a, pb_event_tail, evt_ok
	ret			;event queue is full!  discard event
evt_ok:	mov	pb_event_head, a
	push	dpl
	mov	r1, dph
	mov	dph, #pb_events_page
	mov	dpl, a
	mov	a, r0
        movx	@dptr, a	;put event into the event queue
	mov	dph, r1
	pop	dpl
	ret



	;get the next event from the event queue, Acc=0 for none
get_event:
	clr     et0
        mov     a, pb_event_tail
        cjne    a, pb_event_head, getevt2	;check if buffer empty
        setb    et0
	clr	a
	ret					;no pending events
getevt2:inc     a
	mov     pb_event_tail, a
	mov	dpl, a
	mov	dph, #pb_events_page
	movx	a, @dptr			;read event from queue
	setb	et0
        ret


print_event:
	 ;push	acc
	 ;lcall	phex
	 ;mov	a, #'-'
	 ;lcall	cout
	 ;pop	acc
	acall	event2addr
	mov	r2, #14
	movx	a, @dptr
	jz	pr_evt_done		;don't print anything if null string
pr_evt_loop:
	movx	a, @dptr
	jz	pr_evt_end
	lcall	cout
	inc	dptr
	djnz	r2, pr_evt_loop
pr_evt_end:
	lcall	newline
pr_evt_done:
	ret



event2addr:
	mov	r2, a				;store the event in r2
	anl	a, #15
	add	a, #244
	jc	illegal_event_addr
	mov	a, r2
	swap	a
	anl	a, #15
	dec	a
	mov	r3, a
	add	a, #253
	jc	illegal_event_addr
	mov	a, r2
	anl	a, #15
	mov	b, #3
	mul	ab
	add	a, r3
	mov	b, #14				;strlen max of 14 bytes
	mul	ab
	mov	dpl, a
	mov	a, b
	add	a, #pb_strings_page
	mov	dph, a
	clr	c
	ret
illegal_event_addr:
	mov	dpl, #248
	mov	dph, #pb_strings_page+1
	setb	c
	ret




	


;***********************************************************************
;**                                                                   **
;**                       Serial Port Routines                        **
;**                                                                   **
;***********************************************************************


init_uart_intr:
	clr	ea
        orl     pcon, #10000000b	;set double baud rate
	anl	tmod, #00001111b	;clear all timer1 bits in tmod
	orl	tmod, #00100000b	;set timer1 as 8 bit auto reload
	clr	tr1			;make sure timer1 isn't running
	clr	tf1
        mov     a, #baud_const
        mov     th1, a			;set timer1 rate
        mov     tl1, a
	mov	scon, #01010000b	;config serial port (ri and ti cleared)
        mov     rx_buf_head, #0		;set up empty receive buffer
        mov     rx_buf_tail, #0
        mov     tx_buf_head, #0		;set up transmit buffer as empty
        mov     tx_buf_tail, #0
	clr	tx_intr_expected	;and no tx interrupt expected
	setb	tr1			;start timer1
        setb    es			;enable serial port interrupt
        setb    ea			;also turn on interrupts in general
        ret


;service interrupts generated by the uart... put a received character
;into the receive buffer or get a character from the transmit buffer
;and send it.

uart_intr:
        push    psw
        push    acc
        jb      ti, xmit

recv:   clr     ri
        mov     a, rx_buf_head
        inc     a
	cjne    a, rx_buf_tail, recv_ok         ;check for buffer full
        ;If we got here, the recv buffer is full, so we just
        ;discard this character.  Maybe there should be an overrun
        ;flag so the main program can know some data was lost...
        mov     a, sbuf
        pop     acc
        pop     psw
        reti
recv_ok:mov     rx_buf_head, a  ;update rx_buf_head while it's still in Acc.
	push	dpl
	push	dph
	mov	dph, #rx_buf_page
	mov	dpl, a
        mov	a, sbuf		;get the incoming data
        movx	@dptr, a	;and put it in the buffer
	pop	dph
	pop	dpl
        pop     acc
        pop     psw
        reti

xmit:   clr     ti
        mov     a, tx_buf_tail
        cjne    a, tx_buf_head, xmit_ok		;check for buffer empty
        ;If we got here, there is no data waiting to transmit.  The
        ;uart won't generate more interrupts, so the cout routine had
        ;better check set ti.  tx_buf_head is loaded with zero to that
        ;cout will know to set ti.
	clr	tx_intr_expected
        pop     acc
        pop     psw
        reti
xmit_ok:inc     a
	mov     tx_buf_tail, a  ;update tx_buf_tail while it's still in Acc.
	push	dpl
	push	dph
	mov	dph, #tx_buf_page
	mov	dpl, a
	movx	a, @dptr
	mov	sbuf, a
	pop	dph
	pop	dpl
	setb	tx_intr_expected
        pop     acc
        pop     psw
        reti


;Get a character from the receive buffer.  C=0 if char recv, C=1 if none

cin:	setb	cin_serviced
	clr     es
        mov     a, rx_buf_tail
        cjne    a, rx_buf_head, cin_ok	;check if buffer empty
        setb    es
	setb	c
	ret
cin_ok:	inc     a
	mov     rx_buf_tail, a
	push	dpl
	push	dph
	mov	dpl, a
	mov	dph, #rx_buf_page
	movx	a, @dptr
	pop	dph
	pop	dpl
	setb	es
	clr	c
        ret

;Put the character in Acc into the transmit buffer.  If the buffer is
;full, wait until these is a space to put it.

cout:
        push    psw
        xch     a, r0                           ;put char to send into r0
        push    acc                             ;keep r0 on stack
cout_wt:clr     es
	jb	tx_intr_expected, cout2		;check if not transmitting
        setb    ti              ;set ti in software since buffer is empty
	clr	a
        mov     tx_buf_head, a
        mov     tx_buf_tail, a
	setb	tx_intr_expected
cout2:	mov	a, tx_buf_head
	inc     a
	cjne    a, tx_buf_tail, cout4           ;check if buffer full
        setb    es
        nop                                     ;wait for space in buffer
        sjmp    cout_wt
cout4:  mov     tx_buf_head, a                  ;update tx_buf_head
	push	dph
	push	dpl
	mov	dph, #tx_buf_page
	mov	dpl, a
	xch	a, r0
	movx	@dptr, a
	pop	dpl
	pop	dph
        setb    es
        xch     a, r0                           ;restore r0 value and Acc
        pop     acc
        xch     a, r0
        pop     psw
        ret



; Highly code efficient resursive call phex contributed
; by Alexander B. Alexandrov <[e-mail]>

phex:
phex8:
        acall   phex_b
phex_b: swap    a               ;SWAP A will be twice => A unchanged
phex1:  push    acc
        anl     a, #15
        add     a, #0x90        ; acc is 0x9X, where X is hex digit
        da      a               ; if A to F, C=1 and lower four bits are 0..5
        addc    a, #0x40
        da      a
        lcall   cout
        pop     acc
        ret


newline:push    acc             ;print one newline
        mov     a, #13
        lcall   cout
        mov     a, #10
        lcall   cout
        pop     acc
        ret

pstr:	clr	a
	movc	a, @a+dptr
	inc	dptr
	jz	pstr2
	lcall	cout
	sjmp	pstr
pstr2:	ret


;***********************************************************************
;**                                                                   **
;**                   Fonts and Font Manipulation                     **
;**                                                                   **
;***********************************************************************


	;use the character in Acc and "font" to lookup the 5 byte
	;data to draw a character, and copy it into "char_buf".
lookup_char:
	push	acc
	mov	b, #5
	mul	ab
	mov	dpl, a		;compute offset within font
	mov	dph, b
	mov	a, font
	mov	b, #5
	mul	ab		;compute font's location
	add	a, #fonts_start_page
	add	a, dph
	mov	dph, a		;dptr points to the character we need
	movx	a, @dptr
	mov	char_buf+0, a
	inc	dptr
	movx	a, @dptr
	mov	char_buf+1, a
	inc	dptr
	movx	a, @dptr
	mov	char_buf+2, a
	inc	dptr
	movx	a, @dptr
	mov	char_buf+3, a
	inc	dptr
	movx	a, @dptr
	mov	char_buf+4, a
	pop	acc
	ret



test_font:
	;r6 has the first character to draw
	push	mode_bits
	clr	vscroll_mode
	clr	wrap_mode
	lcall	init_display
	mov	r4, #0
tfont2:
	mov	r5, #16
	mov	x_pos, #8
	mov	y_pos, r4
tfont3:
	mov	a, r6
	push	acc
	lcall	lookup_char
	lcall	cache_char
	pop	acc
	mov	r6, a
	inc	r6
	djnz	r5, tfont3
	inc	r4
	cjne	r4, #8, tfont2
	pop	mode_bits
	ret

;**************************************************************************
;**                                                                      **
;**         Character Caching Routines                                    **
;**                                                                      **
;**************************************************************************

cache_char:
	jb	hscroll_fill_en, hscroll_fill
	mov	a, y_pos		;ignore updates to scrolling rows
	lcall	check_hscroll_en
	jnc	cache_char_ok
	ret
cache_char_ok:
	jnb	update_mode, cache_char_only
	lcall	draw_char
cache_char_only:
	mov	a, x_pos
	add	a, #244
	jnc	cache_char_left
	add	a, #244
	jnc	cache_char_right
	ret

cache_char_right:
	subb	a, #244
	mov	dph, #display_cache+2
	sjmp	cache_display_cont
cache_char_left:
	mov	dph, #display_cache
	mov	a, x_pos
cache_display_cont:
	mov	b, #5			;x_pos*5 to give column address
	mul	ab
	anl	a, #00111111b
	mov	dpl, a
	mov	a, vscroll_offset	;calculate row address
	swap	a
	rl	a
	add	a, y_pos
	anl	a, #00000111b
	swap	a			;mult row address * 64
	clr	c
	rlc	a
	clr	c
	rlc	a
	jnc	cache_char_noovr	;handle overflow into dph
	inc	dph
cache_char_noovr:
	orl	a, dpl
	mov	dpl, a

	;write 5 vertical slices of character
	mov	a, char_buf+0
	movx	@dptr, a
	inc	dptr	
	mov	a, char_buf+1
	movx	@dptr, a
	inc	dptr
	mov	a, char_buf+2
	movx	@dptr, a
	inc	dptr
	mov	a, char_buf+3
	movx	@dptr, a
	inc	dptr
	mov	a, char_buf+4
	movx	@dptr, a

	mov	a, #1
	lcall	move_cursor_right
	ret

hscroll_fill:
	mov	a, hscroll_fill_row
	orl	a, #hscroll_buffer
	mov	dph, a
	anl	a, #00000111b
	add	a, #hscroll_end0
	mov	r0, a
	mov	dpl, @r0
	mov	a, r2
	movx	@dptr, a
	inc	@r0
	ret


clear_cached_display:
	mov	dph, #display_cache
	mov	dpl, #0
	clr	a
clear_cached_display_loop:
	movx	@dptr, a
	inc	dptr
	mov	r0, dph
	cjne	r0, #display_cache+4, clear_cached_display_loop
	ret


copy_fonts_to_sram:
	mov	dptr, #fonts	;dptr = source address
	mov	r0, #0		;r0/r1 = destination address
	mov	r1, #fonts_start_page
cpy_fonts_loop1:
	mov	p2, r1
cpy_fonts_loop2:
	clr	a
	movc	a, @a+dptr
	inc	dptr
	movx	@r0, a
	inc	r0
	cjne	r0, #0, cpy_fonts_loop2
	inc	r1
	cjne	r1, #fonts_start_page + (num_rom_fonts * 5), cpy_fonts_loop1
	mov	p2, #255
	ret

copy_strings_to_sram:
	mov	dptr, #default_event_strings	;dptr = source address
	mov	r0, #0				;r0/r1 = destination address
	mov	r1, #pb_strings_page
cpy_str_loop1:
	mov	p2, r1
cpy_str_loop2:
	clr	a
	movc	a, @a+dptr
	inc	dptr
	movx	@r0, a
	inc	r0
	cjne	r0, #0, cpy_str_loop2
	inc	r1
	cjne	r1, #pb_strings_page + 2, cpy_str_loop1
	mov	p2, #255
	ret

	



msg_font:
	.db	"Font #",0
msg_f0:
	.db	"0 to",0
	.db	"127",0
msg_f128:
	.db	"128 to",0
	.db	"255",0


mesg_abort:
	.db	"Press ESC twice to return to PAULMON2",13,10,13,10,0

mesg_version:
	.db	"VERSION",0

mesg_io_read:
	.db	"IOREAD",0

default_event_strings:
	.db	"b0_down",0,0,0,0,0,0,0
	.db	"b0_up",0,0,0,0,0,0,0,0,0
	.db	"b0_repeat",0,0,0,0,0
	.db	"b1_down",0,0,0,0,0,0,0
	.db	"b1_up",0,0,0,0,0,0,0,0,0
	.db	"b1_repeat",0,0,0,0,0
	.db	"b2_down",0,0,0,0,0,0,0
	.db	"b2_up",0,0,0,0,0,0,0,0,0
	.db	"b2_repeat",0,0,0,0,0
	.db	"b3_down",0,0,0,0,0,0,0
	.db	"b3_up",0,0,0,0,0,0,0,0,0
	.db	"b3_repeat",0,0,0,0,0
	.db	"b4_down",0,0,0,0,0,0,0
	.db	"b4_up",0,0,0,0,0,0,0,0,0
	.db	"b4_repeat",0,0,0,0,0
	.db	"b5_down",0,0,0,0,0,0,0
	.db	"b5_up",0,0,0,0,0,0,0,0,0
	.db	"b5_repeat",0,0,0,0,0
	.db	"b6_down",0,0,0,0,0,0,0
	.db	"b6_up",0,0,0,0,0,0,0,0,0
	.db	"b6_repeat",0,0,0,0,0
	.db	"b7_down",0,0,0,0,0,0,0
	.db	"b7_up",0,0,0,0,0,0,0,0,0
	.db	"b7_repeat",0,0,0,0,0
	.db	"b8_down",0,0,0,0,0,0,0
	.db	"b8_up",0,0,0,0,0,0,0,0,0
	.db	"b8_repeat",0,0,0,0,0
	.db	"b9_down",0,0,0,0,0,0,0
	.db	"b9_up",0,0,0,0,0,0,0,0,0
	.db	"b9_repeat",0,0,0,0,0
	.db	"b10_down",0,0,0,0,0,0
	.db	"b10_up",0,0,0,0,0,0,0,0
	.db	"b10_repeat",0,0,0,0
	.db	"b11_down",0,0,0,0,0,0
	.db	"b11_up",0,0,0,0,0,0,0,0
	.db	"b11_repeat",0,0,0,0
	.db	"error",0,0,0



fonts:
	; this must be the last label of the file, because the build
	; process in the makefile will add the fonts after this point