led2.asm

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY without ev

;+---------------------------------------------------------------------------+
;|                                                                           |
;| Copyright (C) 2002,  Tom De Rybel                                         |
;|                      [e-mail]                                   |
;|                                                                           |
;| 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; either version 2            |
;| of the License, or any later version.                                     |
;|                                                                           |
;| 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.                 |
;|                                                                           |
;|                                                                           |
;+---------------------------------------------------------------------------+
; First test of the Cypress EZ-USB
; Makes a LED connected to PB4 blink
;
; Many thanks to Mr. Tony Cureington for helping me out with this one.
;


;+-------------------------------------+
;| Declaration of the EZ-USB registers |
;+-------------------------------------+
.equ DPL1,	0x84
.equ DPH1,	0x85
.equ DPS,	0x86
.equ CKCON,	0x8E
.equ SPC_FNC,	0x8F
.equ EXIF,	0x91
.equ MPAGE,	0x92
.equ SCON1,	0xC0
.equ SBUF1,	0xC1
.equ EICON,	0xD8
.equ EIE,	0xE8
.equ EIP,	0xF8
		
.equ CPUCS,     0x7F92	
.equ PORTACFG, 	0x7F93
.equ PORTBCFG, 	0x7F94
.equ PORTCCFG, 	0x7F95
.equ OUTA,     	0x7F96	
.equ OUTB,     	0x7F97
.equ OUTC,     	0x7F98
.equ PINSA,    	0x7F99
.equ PINSB,    	0x7F9A
.equ PINSC,    	0x7F9B
.equ OEA,      	0x7F9C
.equ OEB,      	0x7F9D
.equ OEC,      	0x7F9E

;+-------------------+
;| Interrupt vectors |
;+-------------------+
;
;Reset Vector
.org 0x0000
ljmp init


.org 0x0100
;+-------------------------+
;| Initialisation sequence |
;+-------------------------+    
init:
	;;mov	0x92, #0x7F	; tc, allows movx Ri to access ez-usb memory

	mov dptr, #PORTBCFG	; All pins are standard PB pins
	mov a, #00000000b
	movx @dptr, a
	
	mov dptr, #OEB		; Pin PB4 is an output pin
	mov a, #00010000b
	movx @dptr, a


;+--------------+
;| Main program |
;+--------------+		
begin:		
	mov dptr, #OUTB
	mov a, #00010000b
	movx @dptr, a

	lcall  Wait100msec
	lcall  Wait100msec
	lcall  Wait100msec
	
	mov dptr, #OUTB
	mov a, #00000000b
	movx @dptr, a

	lcall  Wait100msec
	lcall  Wait100msec
	lcall  Wait100msec

	ljmp begin


;+---------------------------------------------------------------------+
;| Timing loop taken from the buttons and lights example in USB Design |
;| by Example.                                                         |
;+---------------------------------------------------------------------+
Wait100msec:
        mov     r0, #100
Wait1msec:                      ; A delay loop
        mov     dptr,#-1200
More:   inc     dptr            ; 3 cycles
        mov     a,dpl           ; + 2
        orl     a,dph           ; + 2
        jnz     More            ; + 3 = 10 cycles x 1200 = 1msec
        djnz    r0, Wait1msec   ; 
        ret