paulmon2.asx

一款MP3 Player Firmware 的原代码,非常有参考价值

; PAULMON2 Built-In Functions, "Glue" to SDCC C Programs
;
; This "glue" allows SDCC-based applications to call the
; built-in functions within PAULMON2.  For more information
; about the PAULMON2 monitor, see the PAULMON2 web page:
;
;       http://www.pjrc.com/tech/8051/paulmon2.html
;
; This code is intended to be built with "asx8051".  A typical
; usage is "asx8051 -slop paulmon2.asx".  asx8051 will produce
; the file "paulmon2.rel".  Your C code that calls these functions
; must include "paulmon2.h" for the function prototypes, and then
; when you link your application, you'll need to include
; "paulmon2.rel" on the command like, like this:
;
; sdcc --code-loc 0x2000 --stack-after-data  yourcode.c  paulmon2.rel
;
; This code is an original work of authorship by Paul Stoffregen
; and has been placed in the PUBLIC DOMAIN.  There is no copyright
; and no license agreement.  You may use this code in any manner
; you wish without a royalty or other conditions, even embedded in
; your own for-profit product.
;
; This code is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty
; of merchantability or fitness for a particular purpose. 


.module paulmon2

; well-known entry points to access PAULMON2's built-in functions
pm2_entry_cout = 0x0030		;Send Acc to serial port
pm2_entry_cin = 0x0032		;Get Acc from serial port
pm2_entry_phex = 0x0034		;Print Hex value of Acc
pm2_entry_phex16 = 0x0036	;Print Hex value of DPTR
pm2_entry_pstr = 0x0038		;Print string pointed to by DPTR,
pm2_entry_upper = 0x0040	;Convert Acc to uppercase
pm2_entry_pint8u = 0x004D	;print Acc at an integer, 0 to 255
pm2_entry_pint8 = 0x0050	;print Acc at an integer, -128 to 127
pm2_entry_pint16u = 0x0053	;print DPTR as an integer, 0 to 65535
pm2_entry_newline = 0x0048	;print CR/LF (13 and 10)
pm2_entry_prgm = 0x0059		;program flash byte in A to @DPTR
pm2_entry_erblock = 0x0067	;PAULMON2 v2.1 req'd
pm2_reentry = 0x006D		;return to PAULMON2 (mp3 player version)

.area CSEG (CODE)

	; void pm2_cout(char c)
_pm2_cout::
	mov	a, dpl
	ljmp	pm2_entry_cout

	; char pm2_cin(void)
_pm2_cin::
	lcall	pm2_entry_cin
	mov	dpl, a
	ret

	; void pm2_phex(unsigned char c)
_pm2_phex::
	mov	a, dpl
	ljmp	pm2_entry_phex

	; void pm2_phex16(unsigned int i)
_pm2_phex16::
	ljmp	pm2_entry_phex16

	; void pm2_pstr(code char *str)
_pm2_pstr::
	ljmp	pm2_entry_pstr

	; char pm2_upper(char c)
_pm2_upper::
	mov	a, dpl
	lcall	pm2_entry_upper
	mov	dpl, a
	ret

	; void pm2_pint8u(unsigned char c)
_pm2_pint8u::
	mov	a, dpl
	ljmp	pm2_entry_pint8u

	; void pm2_pint8(char c)
_pm2_pint8::
	mov	a, dpl
	ljmp	pm2_entry_pint8

	; void pm2_pint16u(unsigned int i)
_pm2_pint16u::
	ljmp	pm2_entry_pint16u

	; void pm2_newline(void)
_pm2_newline::
	ljmp	pm2_entry_newline


	; void pm2_exit(void)
_pm2_exit::
	lcall	0x2042
	clr	ea
	ljmp	pm2_reentry