| /* 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 785 2010-05-30 17:57:07Z 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 */ |
| # ifdef INT0_vect |
| # define USB_INTR_VECTOR INT0_vect // this is the "new" define for the vector |
| # else |
| # define USB_INTR_VECTOR SIG_INTERRUPT0 // this is the "old" vector |
| # endif |
| # 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 |
| # ifdef F_CPU |
| # define USB_CFG_CLOCK_KHZ (F_CPU/1000) |
| # else |
| # error "USB_CFG_CLOCK_KHZ not defined in usbconfig.h and no F_CPU set!" |
| # endif |
| #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 */ |