+++ /dev/null
-/* Name: usbdrvasm.S
- * Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers
- * Author: Christian Starkjohann
- * Creation Date: 2007-06-13
- * Tabsize: 4
- * Copyright: (c) 2007 by OBJECTIVE DEVELOPMENT Software GmbH
- * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
- * Revision: $Id: usbdrvasm.S 761 2009-08-12 16:30:23Z cs $
- */
-
-/*
-General Description:
-This module is the assembler part of the USB driver. This file contains
-general code (preprocessor acrobatics and CRC computation) and then includes
-the file appropriate for the given clock rate.
-*/
-
-#define __SFR_OFFSET 0 /* used by avr-libc's register definitions */
-#include "usbportability.h"
-#include "usbdrv.h" /* for common defs */
-
-/* register names */
-#define x1 r16
-#define x2 r17
-#define shift r18
-#define cnt r19
-#define x3 r20
-#define x4 r21
-#define x5 r22
-#define bitcnt x5
-#define phase x4
-#define leap x4
-
-/* Some assembler dependent definitions and declarations: */
-
-#ifdef __IAR_SYSTEMS_ASM__
- extern usbRxBuf, usbDeviceAddr, usbNewDeviceAddr, usbInputBufOffset
- extern usbCurrentTok, usbRxLen, usbRxToken, usbTxLen
- extern usbTxBuf, usbTxStatus1, usbTxStatus3
-# if USB_COUNT_SOF
- extern usbSofCount
-# endif
- public usbCrc16
- public usbCrc16Append
-
- COMMON INTVEC
-# ifndef USB_INTR_VECTOR
- ORG INT0_vect
-# else /* USB_INTR_VECTOR */
- ORG USB_INTR_VECTOR
-# undef USB_INTR_VECTOR
-# endif /* USB_INTR_VECTOR */
-# define USB_INTR_VECTOR usbInterruptHandler
- rjmp USB_INTR_VECTOR
- RSEG CODE
-
-#else /* __IAR_SYSTEMS_ASM__ */
-
-# ifndef USB_INTR_VECTOR /* default to hardware interrupt INT0 */
-# define USB_INTR_VECTOR SIG_INTERRUPT0
-# endif
- .text
- .global USB_INTR_VECTOR
- .type USB_INTR_VECTOR, @function
- .global usbCrc16
- .global usbCrc16Append
-#endif /* __IAR_SYSTEMS_ASM__ */
-
-
-#if USB_INTR_PENDING < 0x40 /* This is an I/O address, use in and out */
-# define USB_LOAD_PENDING(reg) in reg, USB_INTR_PENDING
-# define USB_STORE_PENDING(reg) out USB_INTR_PENDING, reg
-#else /* It's a memory address, use lds and sts */
-# define USB_LOAD_PENDING(reg) lds reg, USB_INTR_PENDING
-# define USB_STORE_PENDING(reg) sts USB_INTR_PENDING, reg
-#endif
-
-#define usbTxLen1 usbTxStatus1
-#define usbTxBuf1 (usbTxStatus1 + 1)
-#define usbTxLen3 usbTxStatus3
-#define usbTxBuf3 (usbTxStatus3 + 1)
-
-
-;----------------------------------------------------------------------------
-; Utility functions
-;----------------------------------------------------------------------------
-
-#ifdef __IAR_SYSTEMS_ASM__
-/* Register assignments for usbCrc16 on IAR cc */
-/* Calling conventions on IAR:
- * First parameter passed in r16/r17, second in r18/r19 and so on.
- * Callee must preserve r4-r15, r24-r29 (r28/r29 is frame pointer)
- * Result is passed in r16/r17
- * In case of the "tiny" memory model, pointers are only 8 bit with no
- * padding. We therefore pass argument 1 as "16 bit unsigned".
- */
-RTMODEL "__rt_version", "3"
-/* The line above will generate an error if cc calling conventions change.
- * The value "3" above is valid for IAR 4.10B/W32
- */
-# define argLen r18 /* argument 2 */
-# define argPtrL r16 /* argument 1 */
-# define argPtrH r17 /* argument 1 */
-
-# define resCrcL r16 /* result */
-# define resCrcH r17 /* result */
-
-# define ptrL ZL
-# define ptrH ZH
-# define ptr Z
-# define byte r22
-# define bitCnt r19
-# define polyL r20
-# define polyH r21
-# define scratch r23
-
-#else /* __IAR_SYSTEMS_ASM__ */
-/* Register assignments for usbCrc16 on gcc */
-/* Calling conventions on gcc:
- * First parameter passed in r24/r25, second in r22/23 and so on.
- * Callee must preserve r1-r17, r28/r29
- * Result is passed in r24/r25
- */
-# define argLen r22 /* argument 2 */
-# define argPtrL r24 /* argument 1 */
-# define argPtrH r25 /* argument 1 */
-
-# define resCrcL r24 /* result */
-# define resCrcH r25 /* result */
-
-# define ptrL XL
-# define ptrH XH
-# define ptr x
-# define byte r18
-# define bitCnt r19
-# define polyL r20
-# define polyH r21
-# define scratch r23
-
-#endif
-
-#if USB_USE_FAST_CRC
-
-; This implementation is faster, but has bigger code size
-; Thanks to Slawomir Fras (BoskiDialer) for this code!
-; It implements the following C pseudo-code:
-; unsigned table(unsigned char x)
-; {
-; unsigned value;
-;
-; value = (unsigned)x << 6;
-; value ^= (unsigned)x << 7;
-; if(parity(x))
-; value ^= 0xc001;
-; return value;
-; }
-; unsigned usbCrc16(unsigned char *argPtr, unsigned char argLen)
-; {
-; unsigned crc = 0xffff;
-;
-; while(argLen--)
-; crc = table(lo8(crc) ^ *argPtr++) ^ hi8(crc);
-; return ~crc;
-; }
-
-; extern unsigned usbCrc16(unsigned char *argPtr, unsigned char argLen);
-; argPtr r24+25 / r16+r17
-; argLen r22 / r18
-; temp variables:
-; byte r18 / r22
-; scratch r23
-; resCrc r24+r25 / r16+r17
-; ptr X / Z
-usbCrc16:
- mov ptrL, argPtrL
- mov ptrH, argPtrH
- ldi resCrcL, 0xFF
- ldi resCrcH, 0xFF
- rjmp usbCrc16LoopTest
-usbCrc16ByteLoop:
- ld byte, ptr+
- eor resCrcL, byte ; resCrcL is now 'x' in table()
- mov byte, resCrcL ; compute parity of 'x'
- swap byte
- eor byte, resCrcL
- mov scratch, byte
- lsr byte
- lsr byte
- eor byte, scratch
- inc byte
- lsr byte
- andi byte, 1 ; byte is now parity(x)
- mov scratch, resCrcL
- mov resCrcL, resCrcH
- eor resCrcL, byte ; low byte of if(parity(x)) value ^= 0xc001;
- neg byte
- andi byte, 0xc0
- mov resCrcH, byte ; high byte of if(parity(x)) value ^= 0xc001;
- clr byte
- lsr scratch
- ror byte
- eor resCrcH, scratch
- eor resCrcL, byte
- lsr scratch
- ror byte
- eor resCrcH, scratch
- eor resCrcL, byte
-usbCrc16LoopTest:
- subi argLen, 1
- brsh usbCrc16ByteLoop
- com resCrcL
- com resCrcH
- ret
-
-#else /* USB_USE_FAST_CRC */
-
-; This implementation is slower, but has less code size
-;
-; extern unsigned usbCrc16(unsigned char *argPtr, unsigned char argLen);
-; argPtr r24+25 / r16+r17
-; argLen r22 / r18
-; temp variables:
-; byte r18 / r22
-; bitCnt r19
-; poly r20+r21
-; scratch r23
-; resCrc r24+r25 / r16+r17
-; ptr X / Z
-usbCrc16:
- mov ptrL, argPtrL
- mov ptrH, argPtrH
- ldi resCrcL, 0
- ldi resCrcH, 0
- ldi polyL, lo8(0xa001)
- ldi polyH, hi8(0xa001)
- com argLen ; argLen = -argLen - 1: modified loop to ensure that carry is set
- ldi bitCnt, 0 ; loop counter with starnd condition = end condition
- rjmp usbCrcLoopEntry
-usbCrcByteLoop:
- ld byte, ptr+
- eor resCrcL, byte
-usbCrcBitLoop:
- ror resCrcH ; carry is always set here (see brcs jumps to here)
- ror resCrcL
- brcs usbCrcNoXor
- eor resCrcL, polyL
- eor resCrcH, polyH
-usbCrcNoXor:
- subi bitCnt, 224 ; (8 * 224) % 256 = 0; this loop iterates 8 times
- brcs usbCrcBitLoop
-usbCrcLoopEntry:
- subi argLen, -1
- brcs usbCrcByteLoop
-usbCrcReady:
- ret
-; Thanks to Reimar Doeffinger for optimizing this CRC routine!
-
-#endif /* USB_USE_FAST_CRC */
-
-; extern unsigned usbCrc16Append(unsigned char *data, unsigned char len);
-usbCrc16Append:
- rcall usbCrc16
- st ptr+, resCrcL
- st ptr+, resCrcH
- ret
-
-#undef argLen
-#undef argPtrL
-#undef argPtrH
-#undef resCrcL
-#undef resCrcH
-#undef ptrL
-#undef ptrH
-#undef ptr
-#undef byte
-#undef bitCnt
-#undef polyL
-#undef polyH
-#undef scratch
-
-
-#if USB_CFG_HAVE_MEASURE_FRAME_LENGTH
-#ifdef __IAR_SYSTEMS_ASM__
-/* Register assignments for usbMeasureFrameLength on IAR cc */
-/* Calling conventions on IAR:
- * First parameter passed in r16/r17, second in r18/r19 and so on.
- * Callee must preserve r4-r15, r24-r29 (r28/r29 is frame pointer)
- * Result is passed in r16/r17
- * In case of the "tiny" memory model, pointers are only 8 bit with no
- * padding. We therefore pass argument 1 as "16 bit unsigned".
- */
-# define resL r16
-# define resH r17
-# define cnt16L r30
-# define cnt16H r31
-# define cntH r18
-
-#else /* __IAR_SYSTEMS_ASM__ */
-/* Register assignments for usbMeasureFrameLength on gcc */
-/* Calling conventions on gcc:
- * First parameter passed in r24/r25, second in r22/23 and so on.
- * Callee must preserve r1-r17, r28/r29
- * Result is passed in r24/r25
- */
-# define resL r24
-# define resH r25
-# define cnt16L r24
-# define cnt16H r25
-# define cntH r26
-#endif
-# define cnt16 cnt16L
-
-; extern unsigned usbMeasurePacketLength(void);
-; returns time between two idle strobes in multiples of 7 CPU clocks
-.global usbMeasureFrameLength
-usbMeasureFrameLength:
- ldi cntH, 6 ; wait ~ 10 ms for D- == 0
- clr cnt16L
- clr cnt16H
-usbMFTime16:
- dec cntH
- breq usbMFTimeout
-usbMFWaitStrobe: ; first wait for D- == 0 (idle strobe)
- sbiw cnt16, 1 ;[0] [6]
- breq usbMFTime16 ;[2]
- sbic USBIN, USBMINUS ;[3]
- rjmp usbMFWaitStrobe ;[4]
-usbMFWaitIdle: ; then wait until idle again
- sbis USBIN, USBMINUS ;1 wait for D- == 1
- rjmp usbMFWaitIdle ;2
- ldi cnt16L, 1 ;1 represents cycles so far
- clr cnt16H ;1
-usbMFWaitLoop:
- in cntH, USBIN ;[0] [7]
- adiw cnt16, 1 ;[1]
- breq usbMFTimeout ;[3]
- andi cntH, USBMASK ;[4]
- brne usbMFWaitLoop ;[5]
-usbMFTimeout:
-#if resL != cnt16L
- mov resL, cnt16L
- mov resH, cnt16H
-#endif
- ret
-
-#undef resL
-#undef resH
-#undef cnt16
-#undef cnt16L
-#undef cnt16H
-#undef cntH
-
-#endif /* USB_CFG_HAVE_MEASURE_FRAME_LENGTH */
-
-;----------------------------------------------------------------------------
-; Now include the clock rate specific code
-;----------------------------------------------------------------------------
-
-#ifndef USB_CFG_CLOCK_KHZ
-# define USB_CFG_CLOCK_KHZ 12000
-#endif
-
-#if USB_CFG_CHECK_CRC /* separate dispatcher for CRC type modules */
-# if USB_CFG_CLOCK_KHZ == 18000
-# include "usbdrvasm18-crc.inc"
-# else
-# error "USB_CFG_CLOCK_KHZ is not one of the supported crc-rates!"
-# endif
-#else /* USB_CFG_CHECK_CRC */
-# if USB_CFG_CLOCK_KHZ == 12000
-# include "usbdrvasm12.inc"
-# elif USB_CFG_CLOCK_KHZ == 12800
-# include "usbdrvasm128.inc"
-# elif USB_CFG_CLOCK_KHZ == 15000
-# include "usbdrvasm15.inc"
-# elif USB_CFG_CLOCK_KHZ == 16000
-# include "usbdrvasm16.inc"
-# elif USB_CFG_CLOCK_KHZ == 16500
-# include "usbdrvasm165.inc"
-# elif USB_CFG_CLOCK_KHZ == 20000
-# include "usbdrvasm20.inc"
-# else
-# error "USB_CFG_CLOCK_KHZ is not one of the supported non-crc-rates!"
-# endif
-#endif /* USB_CFG_CHECK_CRC */
projects / fnordlicht-mini / blobdiff