usbtors232_sk_eng.asm

USB技术大全-54.8M.zip

		out	outputport,temp0	;vysli von na USB	;ENG;transmit to USB
		brne	SendUSBAnswerLoop	;opakuj pre cely buffer (pokial temp3=0)	;ENG;repeat for all buffer (till temp3=0)

		mov	bitcount,OutBitStuffNumber	;pocitadlo bitov pre bitstuff	;ENG;bits counter for bitstuff
		cpi	bitcount,0		;ak nie je potrebny bitstuff	;ENG;if not be needed bitstuff
		breq	ZeroBitStuf
SendUSBAnswerBitstuffLoop:
		ror	inputbuf		;do carry vysielany bit (v smere naskor LSB a potom MSB)	;ENG;to carry transmiting bit (in direction first LSB then MSB)
		brcs	NoXORBitstuffSend	;ak je jedna - nemen stav na USB	;ENG;if is one - don't change state on USB
		eor	temp0,temp2		;inak sa bude stav menit	;ENG;otherwise state will be changed
NoXORBitstuffSend:
		out	outputport,temp0	;vysli von na USB	;ENG;transmit to USB
		nop				;oneskorenie kvoli casovaniu	;ENG;delay because of timing
		dec	bitcount		;zmensi pocitadlo bitov - podla carry flagu	;ENG;decrement bits counter - according to carry flag
		brne	SendUSBAnswerBitstuffLoop	;ak pocitadlo bitov nie je nulove - opakuj vysielanie s dalsim bitom	;ENG;if bits counter isn't zero - repeat transmiting with next bit
		ld	inputbuf,Y		;oneskorenie 2 cykly	;ENG;delay 2 cycle
ZeroBitStuf:
		nop				;oneskorenie 1 cyklus	;ENG;delay 1 cycle
		cbr	temp0,3
		out	outputport,temp0	;vysli EOP na USB	;ENG;transmit EOP on USB

		ldi	bitcount,5		;pocitadlo oneskorenia: EOP ma trvat 2 bity (16 cyklov pri 12MHz)	;ENG;delay counter: EOP shouls exists 2 bits (16 cycle at 12MHz)
SendUSBWaitEOP:
		dec	bitcount
		brne	SendUSBWaitEOP

		sbi	outputport,DATAminus	;nahodenie DATAminus : kludovy stav na port USB	;ENG;set DATAMINUS : idle state on USB port
		sbi	outputport,DATAminus	;oneskorenie 2 cykly: Idle ma trvat 1 bit (8 cyklov pri 12MHz)	;ENG;delay 2 cycle: Idle should exists 1 bit (8 cycle at 12MHz)
		cbi	USBdirection,DATAplus	;DATAplus ako vstupny	;ENG;DATAPLUS as input
		cbi	USBdirection,DATAminus	;DATAminus ako vstupny	;ENG;DATAMINUS as input
		cbi	outputport,DATAminus	;zhodenie DATAminus : treti stav na port USB	;ENG;reset DATAMINUS : the third state on USB port
		ret
;------------------------------------------------------------------------------------------
ToggleDATAPID:
		lds	temp0,OutputBufferBegin+1	;nahraj posledne PID	;ENG;load last PID
		cpi	temp0,DATA1PID			;ak bolo posledne DATA1PID byte	;ENG;if last was DATA1PID byte
		ldi	temp0,DATA0PID
		breq	SendData0PID			;tak posli nulovu odpoved s DATA0PID	;ENG;then send zero answer with DATA0PID
		ldi	temp0,DATA1PID			;inak posli nulovu odpoved s DATA1PID	;ENG;otherwise send zero answer with DATA1PID
SendData0PID:
		sts	OutputBufferBegin+1,temp0	;DATA0PID byte	;ENG;DATA0PID byte
		ret
;------------------------------------------------------------------------------------------
ComposeZeroDATA1PIDAnswer:
		ldi	temp0,DATA0PID			;DATA0 PID - v skutocnosti sa stoggluje na DATA1PID v nahrati deskriptora	;ENG;DATA0 PID - in the next will be toggled to DATA1PID in load descriptor
		sts	OutputBufferBegin+1,temp0	;nahraj do vyst buffera	;ENG;load to output buffer
ComposeZeroAnswer:
		ldi	temp0,SOPbyte
		sts	OutputBufferBegin+0,temp0	;SOP byte	;ENG;SOP byte
		rcall	ToggleDATAPID			;zmen DATAPID	;ENG;change DATAPID
		ldi	temp0,0x00
		sts	OutputBufferBegin+2,temp0	;CRC byte	;ENG;CRC byte
		sts	OutputBufferBegin+3,temp0	;CRC byte	;ENG;CRC byte
		ldi	ByteCount,2+2			;dlzka vystupneho buffera (SOP a PID + CRC16)	;ENG;length of output buffer (SOP and PID + CRC16)
		ret
;------------------------------------------------------------------------------------------
InitACKBufffer:
		ldi	temp0,SOPbyte
		sts	ACKBufferBegin+0,temp0		;SOP byte	;ENG;SOP byte
		ldi	temp0,ACKPID
		sts	ACKBufferBegin+1,temp0		;ACKPID byte	;ENG;ACKPID byte
		ret
;------------------------------------------------------------------------------------------
SendACK:
		push	USBBufptrY
		push	bitcount
		push	OutBitStuffNumber
		ldi	USBBufptrY,ACKBufferBegin	;pointer na zaciatok ACK buffera	;ENG;pointer to begin of ACK buffer
		ldi	ByteCount,2			;pocet vyslanych bytov (iba SOP a ACKPID)	;ENG;number of transmit bytes (only SOP and ACKPID)
		clr	OutBitStuffNumber
		rcall	SendUSBBuffer
		pop	OutBitStuffNumber
		pop	bitcount
		pop	USBBufptrY
		ret
;------------------------------------------------------------------------------------------
InitNAKBufffer:
		ldi	temp0,SOPbyte
		sts	NAKBufferBegin+0,temp0		;SOP byte	;ENG;SOP byte
		ldi	temp0,NAKPID
		sts	NAKBufferBegin+1,temp0		;NAKPID byte	;ENG;NAKPID byte
		ret
;------------------------------------------------------------------------------------------
SendNAK:
		push	OutBitStuffNumber
		ldi	USBBufptrY,NAKBufferBegin	;pointer na zaciatok ACK buffera	;ENG;pointer to begin of ACK buffer
		ldi	ByteCount,2			;pocet vyslanych bytov (iba SOP a NAKPID)	;ENG;number of transmited bytes (only SOP and NAKPID)
		clr	OutBitStuffNumber
		rcall	SendUSBBuffer
		pop	OutBitStuffNumber
		ret
;------------------------------------------------------------------------------------------
ComposeSTALL:
		ldi	temp0,SOPbyte
		sts	OutputBufferBegin+0,temp0	;SOP byte	;ENG;SOP byte
		ldi	temp0,STALLPID
		sts	OutputBufferBegin+1,temp0	;STALLPID byte	;ENG;STALLPID byte
		ldi	ByteCount,2			;dlzka vystupneho buffera (SOP a PID)	;ENG;length of output buffer (SOP and PID)
		ret
;------------------------------------------------------------------------------------------
DecodeNRZI:	;enkodovanie buffera z NRZI kodu do binarneho	;ENG;encoding of buffer from NRZI code to binary
		push	USBBufptrY		;zalohuj pointer do buffera	;ENG;back up pointer to buffer
		push	ByteCount		;zalohuj dlzku buffera	;ENG;back up length of buffer
		add	ByteCount,USBBufptrY	;koniec buffera do ByteCount	;ENG;end of buffer to ByteCount
		ser	temp0			;na zabezpecenie jednotkoveho carry (v nasledujucej rotacii)	;ENG;to ensure unit carry (in the next rotation)
NRZIloop:
		ror	temp0			;naplnenie carry z predchadzajuceho byte	;ENG;filling carry from previous byte
		ld	temp0,Y			;nahraj prijaty byte z buffera	;ENG;load received byte from buffer
		mov	temp2,temp0		;posunuty register o jeden bit vpravo a XOR na funkciu NRZI dekodovania	;ENG;shifted register to one bit to the right and XOR for function of NRZI decoding
		ror	temp2			;carry do najvyssieho bitu a sucasne posuv	;ENG;carry to most significant digit bit and shift
		eor	temp2,temp0		;samotne dekodovanie NRZI	;ENG;NRZI decoding
		com	temp2			;negovanie	;ENG;negate
		st	Y+,temp2		;ulozenie spat ako dekodovany byte a zvys pointer do buffera	;ENG;save back as decoded byte and increment pointer to buffer
		cp	USBBufptrY,ByteCount	;ak este neboli vsetky	;ENG;if not all bytes
		brne	NRZIloop		;tak opakuj	;ENG;then repeat
		pop	ByteCount		;obnov dlzku buffera	;ENG;restore buffer length
		pop	USBBufptrY		;obnov pointer do buffera	;ENG;restore pointer to buffer
		ret				;inak skonci	;ENG;otherwise finish
;------------------------------------------------------------------------------------------
BitStuff:	;odstranenie bit-stuffingu v buffri	;ENG;removal of bitstuffing in buffer
		clr	temp3			;pocitadlo vynechanych bitov	;ENG;counter of omitted bits
		clr	lastBitstufNumber	;0xFF do lastBitstufNumber	;ENG;0xFF to lastBitstufNumber
		dec	lastBitstufNumber
BitStuffRepeat:
		push	USBBufptrY		;zalohuj pointer do buffera	;ENG;back up pointer to buffer
		push	ByteCount		;zalohuj dlzku buffera	;ENG;back up buffer length
		mov	temp1,temp3		;pocitadlo vsetkych bitov	;ENG;counter of all bits
		ldi	temp0,8			;spocitat vsetky bity v bufferi	;ENG;sum all bits in buffer
SumAllBits:
		add	temp1,temp0
		dec	ByteCount
		brne	SumAllBits
		ldi	temp2,6			;inicializuj pocitadlo jednotiek	;ENG;initialize counter of ones
		pop	ByteCount		;obnov dlzku buffera	;ENG;restore buffer length
		push	ByteCount		;zalohuj dlzku buffera	;ENG;back up buffer length
		add	ByteCount,USBBufptrY	;koniec buffera do ByteCount	;ENG;end of buffer to ByteCount
		inc	ByteCount		;a pre istotu ho zvys o 2 (kvoli posuvaniu)	;ENG;and for safety increment it with 2 (because of shifting)
		inc	ByteCount
BitStuffLoop:
		ld	temp0,Y			;nahraj prijaty byte z buffera	;ENG;load received byte from buffer
		ldi	bitcount,8		;pocitadlo bitov v byte	;ENG;bits counter in byte
BitStuffByteLoop:
		ror	temp0			;naplnenie carry z LSB	;ENG;filling carry from LSB
		brcs	IncrementBitstuff	;ak LSB=0	;ENG;if that LSB=0
		ldi	temp2,7			;inicializuj pocitadlo jednotiek +1 (ak bola nula)	;ENG;initialize counter of ones +1 (if was zero)
IncrementBitstuff:
		dec	temp2			;zniz pocitadlo jednotiek (predpoklad jednotkoveho bitu)	;ENG;decrement counter of ones (assumption of one bit)
		brne	DontShiftBuffer		;ak este nebolo 6 jednotiek za sebou - neposun buffer	;ENG;if there was not 6 ones together - don't shift buffer
		cp	temp1,lastBitstufNumber	;
		ldi	temp2,6			;inicializuj pocitadlo jednotiek (ak by sa nerobil bitstuffing tak sa musi zacat odznova)	;ENG;initialize counter of ones (if no bitstuffing will be made then must be started again)
		brcc	DontShiftBuffer		;ak sa tu uz robil bitstuffing - neposun buffer	;ENG;if already was made bitstuffing - don't shift buffer

		dec	temp1	;
		mov	lastBitstufNumber,temp1	;zapamataj si poslednu poziciu bitstuffingu	;ENG;remember last position of bitstuffing
		cpi	bitcount,1		;aby sa ukazovalo na 7 bit (ktory sa ma vymazat alebo kde sa ma vlozit nula)	;ENG;for pointing to 7-th bit (which must be deleted or where to insert zero)
		brne	NoBitcountCorrect
		ldi	bitcount,9	;
		inc	USBBufptrY		;zvys pointer do buffera	ENG;increment pointer to buffer
NoBitcountCorrect:
		dec	bitcount
		bst	BitStuffInOut,0
		brts	CorrectOutBuffer	;ak je Out buffer - zvys dlzku buffera	;ENG;if this is Out buffer - increment buffer length
		rcall	ShiftDeleteBuffer	;posun In buffer	;ENG;shift In buffer
		dec	temp3			;zniz pocitadlo vynechani	;ENG;decrement counter of omission
		rjmp	CorrectBufferEnd
CorrectOutBuffer:
		rcall	ShiftInsertBuffer	;posun Out buffer	;ENG;shift Out buffer
		inc	temp3			;zvys pocitadlo vynechani	;ENG;increment counter of omission
CorrectBufferEnd:
		pop	ByteCount		;obnov dlzku buffera	;ENG;restore buffer length
		pop	USBBufptrY		;obnov pointer do buffera	;ENG;restore pointer to buffer
		rjmp	BitStuffRepeat		;a restartni od zaciatku	;ENG;and restart from begin
DontShiftBuffer:
		dec	temp1			;ak uz boli vsetky bity	;ENG;if already were all bits
		breq	EndBitStuff		;ukonci cyklus	;ENG;finish cycle
		dec	bitcount		;zniz pocitadlo bitov v byte	;ENG;decrement bits counter in byte
		brne	BitStuffByteLoop	;ak este neboli vsetky bity v byte - chod na dalsi bit	;ENG;if not yet been all bits in byte - go to next bit
						;inak nahraj dalsi byte	;ENG;otherwise load next byte
		inc	USBBufptrY		;zvys pointer do buffera	;ENG;increment pointer to buffer
		rjmp	BitStuffLoop		;a opakuj	;ENG;and repeat
EndBitStuff:
		pop	ByteCount		;obnov dlzku buffera	;ENG;restore buffer length
		pop	USBBufptrY		;obnov pointer do buffera	;ENG;restore pointer to buffer
		bst	BitStuffInOut,0
		brts	IncrementLength		;ak je Out buffer - zvys dlzku Out buffera	;ENG;if this is Out buffer - increment length of Out buffer
DecrementLength:				;ak je In buffer - zniz dlzku In buffera	;ENG;if this is In buffer - decrement length of In buffer
		cpi	temp3,0			;bolo aspon jedno znizenie	;ENG;was at least one decrement
		breq	NoChangeByteCount	;ak nie - nemen dlzku buffera	;ENG;if no - don't change buffer length
		dec	ByteCount		;ak je In buffer - zniz dlzku buffera	;ENG;if this is In buffer - decrement buffer length
		subi	temp3,256-8		;ak nebolo viac ako 8 bitov naviac	;ENG;if there wasn't above 8 bits over
		brcc	NoChangeByteCount	;tak skonci	;ENG;then finish
		dec	ByteCount		;inak este zniz dlzku buffera	;ENG;otherwise next decrement buffer length
		ret				;a skonci	;ENG;and finish
IncrementLength:
		mov	OutBitStuffNumber,temp3	;zapamataj si pocet bitov naviac	;ENG;remember number of bits over
		subi	temp3,8			;ak nebolo viac ako 8 bitov naviac	;ENG;if there wasn't above 8 bits over
		brcs	NoChangeByteCount	;tak skonci	;ENG;then finish
		inc	ByteCount		;inak zvys dlzku buffera	;ENG;otherwise increment buffer length
		mov	OutBitStuffNumber,temp3	;a zapamataj si pocet bitov naviac (znizene o 8)	;ENG;and remember number of bits over (decremented by 8)
NoChangeByteCount:
		ret				;skonci	;ENG;finish
;------------------------------------------------------------------------------------------
ShiftInsertBuffer:	;posuv buffer o jeden bit vpravo od konca az po poziciu: byte-USBBufptrY a bit-bitcount	;ENG;shift buffer by one bit to right from end till to position: byte-USBBufptrY and bit-bitcount
		mov	temp0,bitcount		;vypocet: bitcount= 9-bitcount	;ENG;calculation: bitcount= 9-bitcount
		ldi	bitcount,9
		sub	bitcount,temp0		;do bitcount poloha bitu, ktory treba nulovat	;ENG;to bitcount bit position, which is necessary to clear

		ld	temp1,Y			;nahraj byte ktory este treba posunut od pozicie bitcount	;ENG;load byte which still must be shifted from position bitcount
		rol	temp1			;a posun vlavo cez Carry (prenos z vyssieho byte a LSB do Carry)	;ENG;and shift to the left through Carry (transmission from higher byte and LSB to Carry)
		ser	temp2			;FF do masky - temp2	;ENG;FF to mask - temp2