pcode.asm

web51的开发库

; P-Code Interpreter (c)Copyright 2000, Radek Benedikt
;	[e-mail], http://benedikt.lphard.cz

; History: 1.00 -- Radek Benedikt 31-Oct-2000
;  initial version
;*************************************************************
;***		PROJECT WWW8052  http://8052.lphard.cz	    **
;*************************************************************

;   This program is free software; you can redistribute it and/or modify
;   it under the terms of the GNU General Public License as published by
;   the Free Software Foundation, version 2.
;
;   This program 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.  See the
;   GNU General Public License for more details.
;
;   You should have received a copy of the GNU General Public License
;   along with this program; if not, write to the Free Software
;   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

;   Tento program je volne programove vybaveni; muzete jej sirit a
;   modifikovat podle ustanoveni Obecne verejne licence GNU, vydavane Free
;   Software Foundation, verze 2
;
;   Tento program je rozsirovan v nadeji, ze bude uzitecny, avsak BEZ
;   JAKEKOLI ZARUKY; neposkytuji se ani odvozene zaruky PRODEJNOSTI anebo
;   VHODNOSTI PRO URCITY UCEL.
;   Dalsi podrobnosti hledejte v Obecne verejne licenci GNU.
;
;   Kopii Obecne verejne licence GNU jste mel obdrzet spolu s timto
;   programem; pokud se tak nestalo, napiste o ni Free Software Foundation,
;   Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
;

	.global	pcode
	.global	pcall
	.global	pret
	.global	pjumpeq
	.global	pjump
	.global	pjumpne
	.global	pjumpCarry
	.global	pjumpnCarry
	.global	pjumpZero
	.global	pjumpnZero
	.global	zflag
	.global	cflag
	.global	pcodeLSB
	.global	pcodeMSB

;
	.bcomm	token, 1
	.bcomm	pcodeOption, 1
;
;;***** Pcode status flags *****
	.bitcomm zflag, 1		;Zero flag
	.bitcomm cflag, 1		;Carry flag
;
	.comm	pcodeMSB, 1
	.comm	pcodeLSB, 1
;
	.text
;
; *** PCALL *** Call ***
; pcall	address
;	R6R7
pcall:	;mov	a,#'>'
	;lcall	putchar
	POP	DPH	;pop return address (Pcode0)
	POP	DPL
	PUSH	pcodeLSB	;push Pcode return address
	PUSH	pcodeMSB
	MOV	DPH,R6		;new Pcode pointer
	MOV	DPL,R7
	SJMP	Pcode00
;
; *** PRET *** Return ***
; pret
pret:	;mov	a,#'<'
	;lcall	putchar
	POP	DPH	;pop return address (Pcode0)
	POP	DPL
	POP	DPH	;pop Pcode return address
	POP	DPL
	SJMP	Pcode00
;
; *** PJUMPEQ *** Jump if zflag is set ***
; *** PJUMPZERO *** Jump if zflag is set ***
; pjumpeq	address
;	R6R7
pjumpZero:
pjumpeq:JNB	zflag,NoJump
;
; *** PJUMP *** Jump ***
; pjump	address
;	R6R7
pjump:
Jump:	POP	DPH	;pop return address
	POP	DPL
	MOV	pcodeMSB,R6	;new Pcode pointer
	MOV	pcodeLSB,R7
	SJMP	Pcode0
; *** PJUMPNE *** Jump if zflag is not set ***
; *** PJUMPNZERO *** Jump if zflag is not set ***
; pjumpne	address
;	R6R7
pjumpnZero:
pjumpne:JNB	zflag,Jump
NoJump:	RET
;
; *** PJUMPCARRY *** Jump if Cflag is set ***
pjumpCarry:	JB	cflag,Jump
		RET
;
; *** PJUMPNCARRY *** Jump if Cflag is not set ***
pjumpnCarry:	JNB	cflag,Jump
		RET

pcode:
	pop	dph		;get token address
	pop	dpl		;from stack
;	push	pcodeLSB
;	push	pcodeMSB
	MOV	pcodeMSB,DPH
	MOV	pcodeLSB,DPL
Pcode0:	MOV	DPH,pcodeMSB
	MOV	DPL,pcodeLSB
Pcode00:CLR	A
	MOVC	A,@A+DPTR  	;get token
	CJNE	A,#0,Pcode1	;exec token
	INC	DPTR		;end of token
;	pop	pcodeMSB
;	pop	pcodeLSB
	push	dpl		;push return address on stack
	push	dph
	RET
;
Pcode1:	MOV	token,A		;save token MSB
	MOV	A,#LOW(Pcode0)	;push return address
	PUSH	Acc
	MOV	A,#HIGH(Pcode0)
	PUSH	Acc
	INC	DPTR
	CLR	A
	MOV	R7,A
	MOV	R6,A
	MOV	R5,A
	MOV	R4,A
	MOV	R3,A
	MOV	R2,A
	MOVC	A,@A+DPTR  	;get token LSB
	PUSH	Acc		;push LSB
	MOV	A,token
	ANL	A,#0b00011111
	PUSH	Acc		;push MSB
	INC	DPTR
	CLR	A
	MOVC	A,@A+DPTR  	;get option
	MOV	pcodeOption,A
	INC	DPTR
	jnb	B2B(pcodeOption, 7), NoOpt7
	CLR	A
	MOVC	A,@A+DPTR  	;get par1 MSB
	MOV	R6,A		;par1 - R6R7
	INC	DPTR
NoOpt7:	jnb	B2B(pcodeOption, 6), NoOpt6
	CLR	A
	MOVC	A,@A+DPTR  	;get par1 LSB
	MOV	R7,A
	INC	DPTR
NoOpt6:	jnb	B2B(pcodeOption, 5), NoOpt5
	CLR	A
	MOVC	A,@A+DPTR  	;get par2 MSB
	MOV	R4,A		;par2 - R4R5
	INC	DPTR
NoOpt5:	jnb	B2B(pcodeOption, 4), NoOpt4
	CLR	A
	MOVC	A,@A+DPTR  	;get par2 LSB
	MOV	R5,A
	INC	DPTR
NoOpt4:	jnb	B2B(pcodeOption, 3), NoOpt3
	CLR	A
	MOVC	A,@A+DPTR  	;get par3 MSB
	MOV	R2,A		;par3 - R2R3
	INC	DPTR
NoOpt3:	jnb	B2B(pcodeOption, 2), NoOpt2
	CLR	A
	MOVC	A,@A+DPTR  	;get par3 LSB
	MOV	R3,A
	INC	DPTR
NoOpt2:	JNB	B2B(token, 7), noI1
	MOV	A,R7
	MOV	R0,A
	MOV	A,@R0
	MOV	R6,A
	INC	R0
	MOV	A,@R0
	MOV	R7,A
noI1:	JNB	B2B(token, 6), noI2
	MOV	A,R5
	MOV	R0,A
	MOV	A,@R0
	MOV	R4,A
	INC	R0
	MOV	A,@R0
	MOV	R5,A
noI2:	JNB	B2B(token, 5), noI3
	MOV	A,R3
	MOV	R0,A
	MOV	A,@R0
	MOV	R2,A
	INC	R0
	MOV	A,@R0
	MOV	R3,A
noI3:	jnb	B2B(pcodeOption, 1), NoOpt1
	MOV	A,R6	;swap1
	XCH	A,R7
	MOV	R6,A
;	MOV	A,R4	;swap2
;	XCH	A,R5
;	MOV	R4,A
NoOpt1:	jnb	B2B(pcodeOption, 0), NoOpt0
	MOV	A,R2	;swap3
	XCH	A,R3
	MOV	R2,A
NoOpt0:	MOV	pcodeMSB,DPH
	MOV	pcodeLSB,DPL
	RET			;and exec

	;; END