www.pudn.com > EzBulk_asm.rar > Ezbulk.a51

;-------------------------------------------------------------- 
; ezbulk.A51 6-17-98   LTH 
; 
; A Simple bulk transfer.  Updated and corrected version of the 
; example code on page 81 of the EZ-USB TRM v1.0.  Use this to study bulk transfers 
; between the EZ-USB Development Board and the Anchor Control Panel. 
; 
; 1. Fills the EP2IN buffer with a decrementing count from 64 to 1. 
; 2. Maintains counts of number of IN and OUT transfers to EP2. 
; 3. Does nothing with the data received over EP2OUT. 
; 4. Updates the first two bytes of the EP2IN buffer with the number 
;    of EP2IN transfers (byte 0) and the number of OUT transfers (byte 1). 
; 
; To exercise with the Anchor control panel: 
; 1. Download the code, either from the Keil environment or by clicking the  
;    'Download' button and selecting ezbulk.hex. 
; 2. Set Interface 0, alternate setting 1.  This establishes the EP2 endpoints 
;    with MaxPacketSizes of 64. 
; 3. Select Endpoint 2 IN in the Bulk Transfer button bar. 
; 4. Click the Blk Trans button.  You should see the 64 bytes decrementing from  
;    64 to 1. 
; 5. Click Blk Trans button again to perform another EP2IN transfer.  The pattern 
;    should now be the same except for byte 0, which indicates 1 IN transfer has 
;    previously happened.  Each click of BlkTrans button with EP2IN selected transfers 
;    another 64 bytes with the first byte incrementing. 
; 6. Select Endpoint 2 OUT in the Bulk Transfer button bar. 
; 7. Click BlkTrans.  This sends 64 bytes to EP2OUT.  The data is ignored. 
; 8. Select Endpoint 2 IN, click BlkTrans.  The second byte should now be 1, indicating 
;    that one EP2OUT transfer has previously happened.  
; 
; This code polls the endpoint busy bits.  A more advanced example would use the vectored 
; interrupts. 
;-------------------------------------------------------------- 
$NOMOD51		; disable predefined 8051 registers 
$nolist 
$include (..\..\..\target\inc\ezregs.inc)	; EZ-USB register assignments 
$list 
; 
NAME	        ezbulk 
; 
		ISEG AT 60H		; stack (this app doesn't use it) 
stack:		ds	20 
; 
		CSEG AT 0 
 		ljmp	start 
; ------------------------------------------------- 
		org	200h		 
; ------------------------------------------------- 
start:		mov	SP,#STACK-1	; set stack 
		mov	dptr,#IN2BUF 
 		mov	r7,#64		; fill EP2IN buffer with 64 bytes 
fill:		mov	a,r7 
		movx	@dptr,a 
 		inc	dptr 
  		djnz	r7,fill		; load decrementing counter starting w. 64 
; 
		mov	r1,#0		; count the IN transfers 
 		mov	r2,#0		; count the OUT transfers 
  		mov	dptr,#IN2BC	; load the IN2 Byte Count register 
   		mov	a,#64		; 64 bytes 
    		movx	@dptr,a		; arm the IN transfer 
; 
loop:		mov	dptr,#IN2CS	; EP2IN Control & Status register 
		movx	a,@dptr 
 		jnb	acc.1,service_IN2 ; check the busy bit, service if LOW 
  		mov	dptr,#OUT2CS	; EP2OUT Control & Status reg 
   		movx	a,@dptr 
    		jb	acc.1,loop	; busy-keep checking 
; 
service_OUT2:	inc	r2		; OUT packet counter 
		mov	dptr,#IN2BUF+1	; load OUT packet count into second IN2BUF byte 
 		mov	a,r2 
  		movx	@dptr,a 
		mov	dptr,#OUT2BC	; load anything to byte count to re-arm 
 		mov	a,#1		; any value 
 		movx	@dptr,a		 
  		sjmp	loop 
; 
service_IN2:	inc	r1		; IN packet countr 
		mov	dptr,#IN2BUF 
 		mov	a,r1		; load IN packet count into first IN2BUF byte 
  		movx	@dptr,a 
      		mov	dptr,#IN2BC	; load the EP2IN byte count to re-arm IN transfer 
       		mov	a,#64		; 64 byte payload 
       		movx	@dptr,a 
       		sjmp	loop	 
; 
		END