myisr.s

实现基于ip2022的MPEG2 TS的IP组播接收

	.sect	.isr.inline,"ax",@progbits
	.global	_isr_timer2
	.func	isr_timer2,_isr_timer2

_isr_timer2:	; Average expense = 39.5 cycles (when Valid pin high)
		snb	T2CFG1H,2 ; T2CAP2IF
		sb	TCTRL, 5 ;Timer2 intterupt enabled?
		jmp	_wnp_end
		clrb	T2CFG1H,2
		
		;A test
		;mov	w,_np_off
		;sub	w,#1
		;mov	_np_off,w
		;setb	RBOUT,4
		;snz	
		;clrb	RBOUT,4
		;jmp	_wnp_end
		;end of test
				
		;push	STATUS
		test 	_np_off
		snz
		jmp	_wnp_validpin

	_wnp_send:	
		push 	ADDRSEL
		push	ADDRX
		push	ADDRH
		push	ADDRL
		push	DATAH
		push	DATAL
		
		mov	w, #6   ;APP_ADDRSEL_SRC
		mov	ADDRSEL, w
		clr	ADDRX
		mov 	w,_np
		mov     ADDRH,w
		mov	w,_np_off
		sub 	w,#188
		mov     ADDRL,w
		iread
		mov	w, DATAH
		snb	ADDRL, 0
		mov	w, DATAL
		mov	RDOUT, w
		
		;dec	_np_off
		
		pop	DATAL
		pop	DATAH
		pop	ADDRL
		pop	ADDRH
		pop	ADDRX
		pop	ADDRSEL
		
		decsz 	_np_off
		jmp	_wnp_end
		jmp	_wnp_nextpkg
		
	_wnp_validpin:
		snb	_npst,0	;need to clear?
		jmp	_wnp_clrvalidpin	
		sb	_npst,1		; Data ready?
		jmp	_wnp_end
		setb	RBOUT,4   	; make VALID signal low
		clrb	_npst,1
		mov	w,#188
		mov	_np_off,w	; Start to send next package
		jmp	_wnp_send
				
	_wnp_clrvalidpin:
		clrb	RBOUT,4   	; make VALID signal low
		clrb	_npst,0
		jmp	_wnp_end		
		
	_wnp_nextpkg:
		setb	_npst,0	;Need to clear VALID signal
		sb	_npst,2 ;np1 act->skip
		jmp	_wnp_tonp1
		
		mov	w,_np2
		mov	_np,w
		clrb	_npst,2 ;np2 act
		setb	_npst,3
		jmp	_wnp_end	
		
	_wnp_tonp1:
		mov	w,_np1
		mov	_np,w
		clrb	_npst,3 ;np1 act
		setb	_npst,2
				
	_wnp_end:
		;pop	STATUS
		
	.endfunc