fifo_rd_xd.asm

USB CDC using C8051F320/340, virtual COM port thru usb connection

;--------------------------------------------------------
; File Created by SDCC : FreeWare ANSI-C Compiler
; Version 2.5.5 #1236 (Apr  6 2006)
; This file generated Tue Jul 18 06:44:16 2006
;--------------------------------------------------------
	.module FIFO_RD_XD
	.optsdcc -mmcs51 --model-small
;--------------------------------------------------------
; Public variables in this module
;--------------------------------------------------------
	.globl _FIFO_Read_xdata_PARM_3
	.globl _FIFO_Read_xdata_PARM_2
	.globl _FIFO_Read_xdata
;--------------------------------------------------------
; special function registers
;--------------------------------------------------------
	.area RSEG    (DATA)
_USB0ADR	=	0x0096
_USB0DAT	=	0x0097
;--------------------------------------------------------
; overlayable register banks
;--------------------------------------------------------
	.area REG_BANK_0	(REL,OVR,DATA)
	.ds 8
;--------------------------------------------------------
; internal ram data
;--------------------------------------------------------
	.area DSEG    (DATA)
;--------------------------------------------------------
; overlayable items in internal ram 
;--------------------------------------------------------
	.area	OSEG    (OVR,DATA)
_FIFO_Read_xdata_PARM_2::
	.ds 1
_FIFO_Read_xdata_PARM_3::
	.ds 2
;--------------------------------------------------------
; code
;--------------------------------------------------------
	.area CSEG    (CODE)
;------------------------------------------------------------
; void FIFO_Read_xdata( BYTE fifo_adr, BYTE n, BYTE xdata * ptr )
;
;fifo_adr                  Allocated to registers dpl
;n                         Allocated with name '_FIFO_Read_xdata_PARM_2'
;ptr                       Allocated with name '_FIFO_Read_xdata_PARM_3'
;------------------------------------------------------------

_FIFO_Read_xdata:
	mov	a,_FIFO_Read_xdata_PARM_2
	jz	00117$
	mov	r4,a
	mov	r2,dpl
	mov	dpl,_FIFO_Read_xdata_PARM_3
	mov	dph,(_FIFO_Read_xdata_PARM_3 + 1)
	djnz	r4,00105$
	mov	a,#0x80
	orl	a,r2
	mov	_USB0ADR,a
	sjmp 00112$

00105$:
	mov	a,#0xC0
	orl	a,r2
	mov	_USB0ADR,a
00106$:
	mov	a,_USB0ADR
	jb	acc.7,00106$
	mov	a,_USB0DAT
	movx	@dptr,a
	inc	dptr
	djnz	r4,00106$
00112$:
	mov	a,_USB0ADR
	jb	acc.7,00112$
	mov	_USB0ADR,#0x00
	mov	a,_USB0DAT
	movx	@dptr,a
00117$:
	ret