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Diffstat (limited to 'protocol/vusb/usbdrv/usbdrvasm12.inc')
| -rw-r--r-- | protocol/vusb/usbdrv/usbdrvasm12.inc | 393 |
1 files changed, 0 insertions, 393 deletions
diff --git a/protocol/vusb/usbdrv/usbdrvasm12.inc b/protocol/vusb/usbdrv/usbdrvasm12.inc deleted file mode 100644 index c1167584c..000000000 --- a/protocol/vusb/usbdrv/usbdrvasm12.inc +++ /dev/null @@ -1,393 +0,0 @@ -/* Name: usbdrvasm12.inc - * Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers - * Author: Christian Starkjohann - * Creation Date: 2004-12-29 - * Tabsize: 4 - * Copyright: (c) 2007 by OBJECTIVE DEVELOPMENT Software GmbH - * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt) - * This Revision: $Id: usbdrvasm12.inc 740 2009-04-13 18:23:31Z cs $ - */ - -/* Do not link this file! Link usbdrvasm.S instead, which includes the - * appropriate implementation! - */ - -/* -General Description: -This file is the 12 MHz version of the asssembler part of the USB driver. It -requires a 12 MHz crystal (not a ceramic resonator and not a calibrated RC -oscillator). - -See usbdrv.h for a description of the entire driver. - -Since almost all of this code is timing critical, don't change unless you -really know what you are doing! Many parts require not only a maximum number -of CPU cycles, but even an exact number of cycles! - - -Timing constraints according to spec (in bit times): -timing subject min max CPUcycles ---------------------------------------------------------------------------- -EOP of OUT/SETUP to sync pattern of DATA0 (both rx) 2 16 16-128 -EOP of IN to sync pattern of DATA0 (rx, then tx) 2 7.5 16-60 -DATAx (rx) to ACK/NAK/STALL (tx) 2 7.5 16-60 -*/ - -;Software-receiver engine. Strict timing! Don't change unless you can preserve timing! -;interrupt response time: 4 cycles + insn running = 7 max if interrupts always enabled -;max allowable interrupt latency: 34 cycles -> max 25 cycles interrupt disable -;max stack usage: [ret(2), YL, SREG, YH, shift, x1, x2, x3, cnt, x4] = 11 bytes -;Numbers in brackets are maximum cycles since SOF. -USB_INTR_VECTOR: -;order of registers pushed: YL, SREG [sofError], YH, shift, x1, x2, x3, cnt - push YL ;2 [35] push only what is necessary to sync with edge ASAP - in YL, SREG ;1 [37] - push YL ;2 [39] -;---------------------------------------------------------------------------- -; Synchronize with sync pattern: -;---------------------------------------------------------------------------- -;sync byte (D-) pattern LSb to MSb: 01010100 [1 = idle = J, 0 = K] -;sync up with J to K edge during sync pattern -- use fastest possible loops -;The first part waits at most 1 bit long since we must be in sync pattern. -;YL is guarenteed to be < 0x80 because I flag is clear. When we jump to -;waitForJ, ensure that this prerequisite is met. -waitForJ: - inc YL - sbis USBIN, USBMINUS - brne waitForJ ; just make sure we have ANY timeout -waitForK: -;The following code results in a sampling window of 1/4 bit which meets the spec. - sbis USBIN, USBMINUS - rjmp foundK - sbis USBIN, USBMINUS - rjmp foundK - sbis USBIN, USBMINUS - rjmp foundK - sbis USBIN, USBMINUS - rjmp foundK - sbis USBIN, USBMINUS - rjmp foundK -#if USB_COUNT_SOF - lds YL, usbSofCount - inc YL - sts usbSofCount, YL -#endif /* USB_COUNT_SOF */ -#ifdef USB_SOF_HOOK - USB_SOF_HOOK -#endif - rjmp sofError -foundK: -;{3, 5} after falling D- edge, average delay: 4 cycles [we want 4 for center sampling] -;we have 1 bit time for setup purposes, then sample again. Numbers in brackets -;are cycles from center of first sync (double K) bit after the instruction - push YH ;2 [2] - lds YL, usbInputBufOffset;2 [4] - clr YH ;1 [5] - subi YL, lo8(-(usbRxBuf));1 [6] - sbci YH, hi8(-(usbRxBuf));1 [7] - - sbis USBIN, USBMINUS ;1 [8] we want two bits K [sample 1 cycle too early] - rjmp haveTwoBitsK ;2 [10] - pop YH ;2 [11] undo the push from before - rjmp waitForK ;2 [13] this was not the end of sync, retry -haveTwoBitsK: -;---------------------------------------------------------------------------- -; push more registers and initialize values while we sample the first bits: -;---------------------------------------------------------------------------- - push shift ;2 [16] - push x1 ;2 [12] - push x2 ;2 [14] - - in x1, USBIN ;1 [17] <-- sample bit 0 - ldi shift, 0xff ;1 [18] - bst x1, USBMINUS ;1 [19] - bld shift, 0 ;1 [20] - push x3 ;2 [22] - push cnt ;2 [24] - - in x2, USBIN ;1 [25] <-- sample bit 1 - ser x3 ;1 [26] [inserted init instruction] - eor x1, x2 ;1 [27] - bst x1, USBMINUS ;1 [28] - bld shift, 1 ;1 [29] - ldi cnt, USB_BUFSIZE;1 [30] [inserted init instruction] - rjmp rxbit2 ;2 [32] - -;---------------------------------------------------------------------------- -; Receiver loop (numbers in brackets are cycles within byte after instr) -;---------------------------------------------------------------------------- - -unstuff0: ;1 (branch taken) - andi x3, ~0x01 ;1 [15] - mov x1, x2 ;1 [16] x2 contains last sampled (stuffed) bit - in x2, USBIN ;1 [17] <-- sample bit 1 again - ori shift, 0x01 ;1 [18] - rjmp didUnstuff0 ;2 [20] - -unstuff1: ;1 (branch taken) - mov x2, x1 ;1 [21] x1 contains last sampled (stuffed) bit - andi x3, ~0x02 ;1 [22] - ori shift, 0x02 ;1 [23] - nop ;1 [24] - in x1, USBIN ;1 [25] <-- sample bit 2 again - rjmp didUnstuff1 ;2 [27] - -unstuff2: ;1 (branch taken) - andi x3, ~0x04 ;1 [29] - ori shift, 0x04 ;1 [30] - mov x1, x2 ;1 [31] x2 contains last sampled (stuffed) bit - nop ;1 [32] - in x2, USBIN ;1 [33] <-- sample bit 3 - rjmp didUnstuff2 ;2 [35] - -unstuff3: ;1 (branch taken) - in x2, USBIN ;1 [34] <-- sample stuffed bit 3 [one cycle too late] - andi x3, ~0x08 ;1 [35] - ori shift, 0x08 ;1 [36] - rjmp didUnstuff3 ;2 [38] - -unstuff4: ;1 (branch taken) - andi x3, ~0x10 ;1 [40] - in x1, USBIN ;1 [41] <-- sample stuffed bit 4 - ori shift, 0x10 ;1 [42] - rjmp didUnstuff4 ;2 [44] - -unstuff5: ;1 (branch taken) - andi x3, ~0x20 ;1 [48] - in x2, USBIN ;1 [49] <-- sample stuffed bit 5 - ori shift, 0x20 ;1 [50] - rjmp didUnstuff5 ;2 [52] - -unstuff6: ;1 (branch taken) - andi x3, ~0x40 ;1 [56] - in x1, USBIN ;1 [57] <-- sample stuffed bit 6 - ori shift, 0x40 ;1 [58] - rjmp didUnstuff6 ;2 [60] - -; extra jobs done during bit interval: -; bit 0: store, clear [SE0 is unreliable here due to bit dribbling in hubs] -; bit 1: se0 check -; bit 2: overflow check -; bit 3: recovery from delay [bit 0 tasks took too long] -; bit 4: none -; bit 5: none -; bit 6: none -; bit 7: jump, eor -rxLoop: - eor x3, shift ;1 [0] reconstruct: x3 is 0 at bit locations we changed, 1 at others - in x1, USBIN ;1 [1] <-- sample bit 0 - st y+, x3 ;2 [3] store data - ser x3 ;1 [4] - nop ;1 [5] - eor x2, x1 ;1 [6] - bst x2, USBMINUS;1 [7] - bld shift, 0 ;1 [8] - in x2, USBIN ;1 [9] <-- sample bit 1 (or possibly bit 0 stuffed) - andi x2, USBMASK ;1 [10] - breq se0 ;1 [11] SE0 check for bit 1 - andi shift, 0xf9 ;1 [12] -didUnstuff0: - breq unstuff0 ;1 [13] - eor x1, x2 ;1 [14] - bst x1, USBMINUS;1 [15] - bld shift, 1 ;1 [16] -rxbit2: - in x1, USBIN ;1 [17] <-- sample bit 2 (or possibly bit 1 stuffed) - andi shift, 0xf3 ;1 [18] - breq unstuff1 ;1 [19] do remaining work for bit 1 -didUnstuff1: - subi cnt, 1 ;1 [20] - brcs overflow ;1 [21] loop control - eor x2, x1 ;1 [22] - bst x2, USBMINUS;1 [23] - bld shift, 2 ;1 [24] - in x2, USBIN ;1 [25] <-- sample bit 3 (or possibly bit 2 stuffed) - andi shift, 0xe7 ;1 [26] - breq unstuff2 ;1 [27] -didUnstuff2: - eor x1, x2 ;1 [28] - bst x1, USBMINUS;1 [29] - bld shift, 3 ;1 [30] -didUnstuff3: - andi shift, 0xcf ;1 [31] - breq unstuff3 ;1 [32] - in x1, USBIN ;1 [33] <-- sample bit 4 - eor x2, x1 ;1 [34] - bst x2, USBMINUS;1 [35] - bld shift, 4 ;1 [36] -didUnstuff4: - andi shift, 0x9f ;1 [37] - breq unstuff4 ;1 [38] - nop2 ;2 [40] - in x2, USBIN ;1 [41] <-- sample bit 5 - eor x1, x2 ;1 [42] - bst x1, USBMINUS;1 [43] - bld shift, 5 ;1 [44] -didUnstuff5: - andi shift, 0x3f ;1 [45] - breq unstuff5 ;1 [46] - nop2 ;2 [48] - in x1, USBIN ;1 [49] <-- sample bit 6 - eor x2, x1 ;1 [50] - bst x2, USBMINUS;1 [51] - bld shift, 6 ;1 [52] -didUnstuff6: - cpi shift, 0x02 ;1 [53] - brlo unstuff6 ;1 [54] - nop2 ;2 [56] - in x2, USBIN ;1 [57] <-- sample bit 7 - eor x1, x2 ;1 [58] - bst x1, USBMINUS;1 [59] - bld shift, 7 ;1 [60] -didUnstuff7: - cpi shift, 0x04 ;1 [61] - brsh rxLoop ;2 [63] loop control -unstuff7: - andi x3, ~0x80 ;1 [63] - ori shift, 0x80 ;1 [64] - in x2, USBIN ;1 [65] <-- sample stuffed bit 7 - nop ;1 [66] - rjmp didUnstuff7 ;2 [68] - -macro POP_STANDARD ; 12 cycles - pop cnt - pop x3 - pop x2 - pop x1 - pop shift - pop YH - endm -macro POP_RETI ; 5 cycles - pop YL - out SREG, YL - pop YL - endm - -#include "asmcommon.inc" - -;---------------------------------------------------------------------------- -; Transmitting data -;---------------------------------------------------------------------------- - -txByteLoop: -txBitloop: -stuffN1Delay: ; [03] - ror shift ;[-5] [11] [59] - brcc doExorN1 ;[-4] [60] - subi x4, 1 ;[-3] - brne commonN1 ;[-2] - lsl shift ;[-1] compensate ror after rjmp stuffDelay - nop ;[00] stuffing consists of just waiting 8 cycles - rjmp stuffN1Delay ;[01] after ror, C bit is reliably clear - -sendNakAndReti: ;0 [-19] 19 cycles until SOP - ldi x3, USBPID_NAK ;1 [-18] - rjmp usbSendX3 ;2 [-16] -sendAckAndReti: ;0 [-19] 19 cycles until SOP - ldi x3, USBPID_ACK ;1 [-18] - rjmp usbSendX3 ;2 [-16] -sendCntAndReti: ;0 [-17] 17 cycles until SOP - mov x3, cnt ;1 [-16] -usbSendX3: ;0 [-16] - ldi YL, 20 ;1 [-15] 'x3' is R20 - ldi YH, 0 ;1 [-14] - ldi cnt, 2 ;1 [-13] -; rjmp usbSendAndReti fallthrough - -; USB spec says: -; idle = J -; J = (D+ = 0), (D- = 1) or USBOUT = 0x01 -; K = (D+ = 1), (D- = 0) or USBOUT = 0x02 -; Spec allows 7.5 bit times from EOP to SOP for replies (= 60 cycles) - -;usbSend: -;pointer to data in 'Y' -;number of bytes in 'cnt' -- including sync byte -;uses: x1...x2, x4, shift, cnt, Y [x1 = mirror USBOUT, x2 = USBMASK, x4 = bitstuff cnt] -;Numbers in brackets are time since first bit of sync pattern is sent (start of instruction) -usbSendAndReti: - in x2, USBDDR ;[-12] 12 cycles until SOP - ori x2, USBMASK ;[-11] - sbi USBOUT, USBMINUS ;[-10] prepare idle state; D+ and D- must have been 0 (no pullups) - out USBDDR, x2 ;[-8] <--- acquire bus - in x1, USBOUT ;[-7] port mirror for tx loop - ldi shift, 0x40 ;[-6] sync byte is first byte sent (we enter loop after ror) - ldi x2, USBMASK ;[-5] - push x4 ;[-4] -doExorN1: - eor x1, x2 ;[-2] [06] [62] - ldi x4, 6 ;[-1] [07] [63] -commonN1: -stuffN2Delay: - out USBOUT, x1 ;[00] [08] [64] <--- set bit - ror shift ;[01] - brcc doExorN2 ;[02] - subi x4, 1 ;[03] - brne commonN2 ;[04] - lsl shift ;[05] compensate ror after rjmp stuffDelay - rjmp stuffN2Delay ;[06] after ror, C bit is reliably clear -doExorN2: - eor x1, x2 ;[04] [12] - ldi x4, 6 ;[05] [13] -commonN2: - nop ;[06] [14] - subi cnt, 171 ;[07] [15] trick: (3 * 171) & 0xff = 1 - out USBOUT, x1 ;[08] [16] <--- set bit - brcs txBitloop ;[09] [25] [41] - -stuff6Delay: - ror shift ;[42] [50] - brcc doExor6 ;[43] - subi x4, 1 ;[44] - brne common6 ;[45] - lsl shift ;[46] compensate ror after rjmp stuffDelay - nop ;[47] stuffing consists of just waiting 8 cycles - rjmp stuff6Delay ;[48] after ror, C bit is reliably clear -doExor6: - eor x1, x2 ;[45] [53] - ldi x4, 6 ;[46] -common6: -stuff7Delay: - ror shift ;[47] [55] - out USBOUT, x1 ;[48] <--- set bit - brcc doExor7 ;[49] - subi x4, 1 ;[50] - brne common7 ;[51] - lsl shift ;[52] compensate ror after rjmp stuffDelay - rjmp stuff7Delay ;[53] after ror, C bit is reliably clear -doExor7: - eor x1, x2 ;[51] [59] - ldi x4, 6 ;[52] -common7: - ld shift, y+ ;[53] - tst cnt ;[55] - out USBOUT, x1 ;[56] <--- set bit - brne txByteLoop ;[57] - -;make SE0: - cbr x1, USBMASK ;[58] prepare SE0 [spec says EOP may be 15 to 18 cycles] - lds x2, usbNewDeviceAddr;[59] - lsl x2 ;[61] we compare with left shifted address - subi YL, 2 + 20 ;[62] Only assign address on data packets, not ACK/NAK in x3 - sbci YH, 0 ;[63] - out USBOUT, x1 ;[00] <-- out SE0 -- from now 2 bits = 16 cycles until bus idle -;2006-03-06: moved transfer of new address to usbDeviceAddr from C-Code to asm: -;set address only after data packet was sent, not after handshake - breq skipAddrAssign ;[01] - sts usbDeviceAddr, x2 ; if not skipped: SE0 is one cycle longer -skipAddrAssign: -;end of usbDeviceAddress transfer - ldi x2, 1<<USB_INTR_PENDING_BIT;[03] int0 occurred during TX -- clear pending flag - USB_STORE_PENDING(x2) ;[04] - ori x1, USBIDLE ;[05] - in x2, USBDDR ;[06] - cbr x2, USBMASK ;[07] set both pins to input - mov x3, x1 ;[08] - cbr x3, USBMASK ;[09] configure no pullup on both pins - pop x4 ;[10] - nop2 ;[12] - nop2 ;[14] - out USBOUT, x1 ;[16] <-- out J (idle) -- end of SE0 (EOP signal) - out USBDDR, x2 ;[17] <-- release bus now - out USBOUT, x3 ;[18] <-- ensure no pull-up resistors are active - rjmp doReturn |