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/* Name: usbdrvasm.S
* Project: AVR USB driver
* 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) or proprietary (CommercialLicense.txt)
* Revision: $Id$
*/
/*
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 bitcnt r22
#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
; extern unsigned usbCrc16(unsigned char *data, unsigned char len);
; data: r24/25
; len: r22
; temp variables:
; r18: data byte
; r19: bit counter
; r20/21: polynomial
; r23: scratch
; r24/25: crc-sum
; r26/27=X: ptr
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
crcByteLoop:
subi argLen, -1
brcc crcReady ; modified loop to ensure that carry is set below
ld byte, ptr+
ldi bitCnt, -8 ; strange loop counter to ensure that carry is set where we need it
eor resCrcL, byte
crcBitLoop:
ror resCrcH ; carry is always set here
ror resCrcL
brcs crcNoXor
eor resCrcL, polyL
eor resCrcH, polyH
crcNoXor:
subi bitCnt, -1
brcs crcBitLoop
rjmp crcByteLoop
crcReady:
ret
; Thanks to Reimar Doeffinger for optimizing this CRC routine!
; 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_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 rates!"
#endif
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