diff options
| author | tmk <hasu@tmk-kbd.com> | 2015-04-10 01:25:48 +0900 |
|---|---|---|
| committer | tmk <hasu@tmk-kbd.com> | 2015-04-10 01:25:48 +0900 |
| commit | 6746e37088ce8ba03529c1226bd216705edb2b1f (patch) | |
| tree | a256db88ec3e9e8b1b70839fcd9459d972ce26e0 /protocol/vusb/usbdrv/usbdrvasm12.inc | |
| parent | b4e2d325f355a4d083106476393775e75e11f284 (diff) | |
| download | qmk_firmware-6746e37088ce8ba03529c1226bd216705edb2b1f.tar.gz qmk_firmware-6746e37088ce8ba03529c1226bd216705edb2b1f.zip | |
Remove core library and build files
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 @@ | |||
| 1 | /* Name: usbdrvasm12.inc | ||
| 2 | * Project: V-USB, virtual USB port for Atmel's(r) AVR(r) microcontrollers | ||
| 3 | * Author: Christian Starkjohann | ||
| 4 | * Creation Date: 2004-12-29 | ||
| 5 | * Tabsize: 4 | ||
| 6 | * Copyright: (c) 2007 by OBJECTIVE DEVELOPMENT Software GmbH | ||
| 7 | * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt) | ||
| 8 | * This Revision: $Id: usbdrvasm12.inc 740 2009-04-13 18:23:31Z cs $ | ||
| 9 | */ | ||
| 10 | |||
| 11 | /* Do not link this file! Link usbdrvasm.S instead, which includes the | ||
| 12 | * appropriate implementation! | ||
| 13 | */ | ||
| 14 | |||
| 15 | /* | ||
| 16 | General Description: | ||
| 17 | This file is the 12 MHz version of the asssembler part of the USB driver. It | ||
| 18 | requires a 12 MHz crystal (not a ceramic resonator and not a calibrated RC | ||
| 19 | oscillator). | ||
| 20 | |||
| 21 | See usbdrv.h for a description of the entire driver. | ||
| 22 | |||
| 23 | Since almost all of this code is timing critical, don't change unless you | ||
| 24 | really know what you are doing! Many parts require not only a maximum number | ||
| 25 | of CPU cycles, but even an exact number of cycles! | ||
| 26 | |||
| 27 | |||
| 28 | Timing constraints according to spec (in bit times): | ||
| 29 | timing subject min max CPUcycles | ||
| 30 | --------------------------------------------------------------------------- | ||
| 31 | EOP of OUT/SETUP to sync pattern of DATA0 (both rx) 2 16 16-128 | ||
| 32 | EOP of IN to sync pattern of DATA0 (rx, then tx) 2 7.5 16-60 | ||
| 33 | DATAx (rx) to ACK/NAK/STALL (tx) 2 7.5 16-60 | ||
| 34 | */ | ||
| 35 | |||
| 36 | ;Software-receiver engine. Strict timing! Don't change unless you can preserve timing! | ||
| 37 | ;interrupt response time: 4 cycles + insn running = 7 max if interrupts always enabled | ||
| 38 | ;max allowable interrupt latency: 34 cycles -> max 25 cycles interrupt disable | ||
| 39 | ;max stack usage: [ret(2), YL, SREG, YH, shift, x1, x2, x3, cnt, x4] = 11 bytes | ||
| 40 | ;Numbers in brackets are maximum cycles since SOF. | ||
| 41 | USB_INTR_VECTOR: | ||
| 42 | ;order of registers pushed: YL, SREG [sofError], YH, shift, x1, x2, x3, cnt | ||
| 43 | push YL ;2 [35] push only what is necessary to sync with edge ASAP | ||
| 44 | in YL, SREG ;1 [37] | ||
| 45 | push YL ;2 [39] | ||
| 46 | ;---------------------------------------------------------------------------- | ||
| 47 | ; Synchronize with sync pattern: | ||
| 48 | ;---------------------------------------------------------------------------- | ||
| 49 | ;sync byte (D-) pattern LSb to MSb: 01010100 [1 = idle = J, 0 = K] | ||
| 50 | ;sync up with J to K edge during sync pattern -- use fastest possible loops | ||
| 51 | ;The first part waits at most 1 bit long since we must be in sync pattern. | ||
| 52 | ;YL is guarenteed to be < 0x80 because I flag is clear. When we jump to | ||
| 53 | ;waitForJ, ensure that this prerequisite is met. | ||
| 54 | waitForJ: | ||
| 55 | inc YL | ||
| 56 | sbis USBIN, USBMINUS | ||
| 57 | brne waitForJ ; just make sure we have ANY timeout | ||
| 58 | waitForK: | ||
| 59 | ;The following code results in a sampling window of 1/4 bit which meets the spec. | ||
| 60 | sbis USBIN, USBMINUS | ||
| 61 | rjmp foundK | ||
| 62 | sbis USBIN, USBMINUS | ||
| 63 | rjmp foundK | ||
| 64 | sbis USBIN, USBMINUS | ||
| 65 | rjmp foundK | ||
| 66 | sbis USBIN, USBMINUS | ||
| 67 | rjmp foundK | ||
| 68 | sbis USBIN, USBMINUS | ||
| 69 | rjmp foundK | ||
| 70 | #if USB_COUNT_SOF | ||
| 71 | lds YL, usbSofCount | ||
| 72 | inc YL | ||
| 73 | sts usbSofCount, YL | ||
| 74 | #endif /* USB_COUNT_SOF */ | ||
| 75 | #ifdef USB_SOF_HOOK | ||
| 76 | USB_SOF_HOOK | ||
| 77 | #endif | ||
| 78 | rjmp sofError | ||
| 79 | foundK: | ||
| 80 | ;{3, 5} after falling D- edge, average delay: 4 cycles [we want 4 for center sampling] | ||
| 81 | ;we have 1 bit time for setup purposes, then sample again. Numbers in brackets | ||
| 82 | ;are cycles from center of first sync (double K) bit after the instruction | ||
| 83 | push YH ;2 [2] | ||
| 84 | lds YL, usbInputBufOffset;2 [4] | ||
| 85 | clr YH ;1 [5] | ||
| 86 | subi YL, lo8(-(usbRxBuf));1 [6] | ||
| 87 | sbci YH, hi8(-(usbRxBuf));1 [7] | ||
| 88 | |||
| 89 | sbis USBIN, USBMINUS ;1 [8] we want two bits K [sample 1 cycle too early] | ||
| 90 | rjmp haveTwoBitsK ;2 [10] | ||
| 91 | pop YH ;2 [11] undo the push from before | ||
| 92 | rjmp waitForK ;2 [13] this was not the end of sync, retry | ||
| 93 | haveTwoBitsK: | ||
| 94 | ;---------------------------------------------------------------------------- | ||
| 95 | ; push more registers and initialize values while we sample the first bits: | ||
| 96 | ;---------------------------------------------------------------------------- | ||
| 97 | push shift ;2 [16] | ||
| 98 | push x1 ;2 [12] | ||
| 99 | push x2 ;2 [14] | ||
| 100 | |||
| 101 | in x1, USBIN ;1 [17] <-- sample bit 0 | ||
| 102 | ldi shift, 0xff ;1 [18] | ||
| 103 | bst x1, USBMINUS ;1 [19] | ||
| 104 | bld shift, 0 ;1 [20] | ||
| 105 | push x3 ;2 [22] | ||
| 106 | push cnt ;2 [24] | ||
| 107 | |||
| 108 | in x2, USBIN ;1 [25] <-- sample bit 1 | ||
| 109 | ser x3 ;1 [26] [inserted init instruction] | ||
| 110 | eor x1, x2 ;1 [27] | ||
| 111 | bst x1, USBMINUS ;1 [28] | ||
| 112 | bld shift, 1 ;1 [29] | ||
| 113 | ldi cnt, USB_BUFSIZE;1 [30] [inserted init instruction] | ||
| 114 | rjmp rxbit2 ;2 [32] | ||
| 115 | |||
| 116 | ;---------------------------------------------------------------------------- | ||
| 117 | ; Receiver loop (numbers in brackets are cycles within byte after instr) | ||
| 118 | ;---------------------------------------------------------------------------- | ||
| 119 | |||
| 120 | unstuff0: ;1 (branch taken) | ||
| 121 | andi x3, ~0x01 ;1 [15] | ||
| 122 | mov x1, x2 ;1 [16] x2 contains last sampled (stuffed) bit | ||
| 123 | in x2, USBIN ;1 [17] <-- sample bit 1 again | ||
| 124 | ori shift, 0x01 ;1 [18] | ||
| 125 | rjmp didUnstuff0 ;2 [20] | ||
| 126 | |||
| 127 | unstuff1: ;1 (branch taken) | ||
| 128 | mov x2, x1 ;1 [21] x1 contains last sampled (stuffed) bit | ||
| 129 | andi x3, ~0x02 ;1 [22] | ||
| 130 | ori shift, 0x02 ;1 [23] | ||
| 131 | nop ;1 [24] | ||
| 132 | in x1, USBIN ;1 [25] <-- sample bit 2 again | ||
| 133 | rjmp didUnstuff1 ;2 [27] | ||
| 134 | |||
| 135 | unstuff2: ;1 (branch taken) | ||
| 136 | andi x3, ~0x04 ;1 [29] | ||
| 137 | ori shift, 0x04 ;1 [30] | ||
| 138 | mov x1, x2 ;1 [31] x2 contains last sampled (stuffed) bit | ||
| 139 | nop ;1 [32] | ||
| 140 | in x2, USBIN ;1 [33] <-- sample bit 3 | ||
| 141 | rjmp didUnstuff2 ;2 [35] | ||
| 142 | |||
| 143 | unstuff3: ;1 (branch taken) | ||
| 144 | in x2, USBIN ;1 [34] <-- sample stuffed bit 3 [one cycle too late] | ||
| 145 | andi x3, ~0x08 ;1 [35] | ||
| 146 | ori shift, 0x08 ;1 [36] | ||
| 147 | rjmp didUnstuff3 ;2 [38] | ||
| 148 | |||
| 149 | unstuff4: ;1 (branch taken) | ||
| 150 | andi x3, ~0x10 ;1 [40] | ||
| 151 | in x1, USBIN ;1 [41] <-- sample stuffed bit 4 | ||
| 152 | ori shift, 0x10 ;1 [42] | ||
| 153 | rjmp didUnstuff4 ;2 [44] | ||
| 154 | |||
| 155 | unstuff5: ;1 (branch taken) | ||
| 156 | andi x3, ~0x20 ;1 [48] | ||
| 157 | in x2, USBIN ;1 [49] <-- sample stuffed bit 5 | ||
| 158 | ori shift, 0x20 ;1 [50] | ||
| 159 | rjmp didUnstuff5 ;2 [52] | ||
| 160 | |||
| 161 | unstuff6: ;1 (branch taken) | ||
| 162 | andi x3, ~0x40 ;1 [56] | ||
| 163 | in x1, USBIN ;1 [57] <-- sample stuffed bit 6 | ||
| 164 | ori shift, 0x40 ;1 [58] | ||
| 165 | rjmp didUnstuff6 ;2 [60] | ||
| 166 | |||
| 167 | ; extra jobs done during bit interval: | ||
| 168 | ; bit 0: store, clear [SE0 is unreliable here due to bit dribbling in hubs] | ||
| 169 | ; bit 1: se0 check | ||
| 170 | ; bit 2: overflow check | ||
| 171 | ; bit 3: recovery from delay [bit 0 tasks took too long] | ||
| 172 | ; bit 4: none | ||
| 173 | ; bit 5: none | ||
| 174 | ; bit 6: none | ||
| 175 | ; bit 7: jump, eor | ||
| 176 | rxLoop: | ||
| 177 | eor x3, shift ;1 [0] reconstruct: x3 is 0 at bit locations we changed, 1 at others | ||
| 178 | in x1, USBIN ;1 [1] <-- sample bit 0 | ||
| 179 | st y+, x3 ;2 [3] store data | ||
| 180 | ser x3 ;1 [4] | ||
| 181 | nop ;1 [5] | ||
| 182 | eor x2, x1 ;1 [6] | ||
| 183 | bst x2, USBMINUS;1 [7] | ||
| 184 | bld shift, 0 ;1 [8] | ||
| 185 | in x2, USBIN ;1 [9] <-- sample bit 1 (or possibly bit 0 stuffed) | ||
| 186 | andi x2, USBMASK ;1 [10] | ||
| 187 | breq se0 ;1 [11] SE0 check for bit 1 | ||
| 188 | andi shift, 0xf9 ;1 [12] | ||
| 189 | didUnstuff0: | ||
| 190 | breq unstuff0 ;1 [13] | ||
| 191 | eor x1, x2 ;1 [14] | ||
| 192 | bst x1, USBMINUS;1 [15] | ||
| 193 | bld shift, 1 ;1 [16] | ||
| 194 | rxbit2: | ||
| 195 | in x1, USBIN ;1 [17] <-- sample bit 2 (or possibly bit 1 stuffed) | ||
| 196 | andi shift, 0xf3 ;1 [18] | ||
| 197 | breq unstuff1 ;1 [19] do remaining work for bit 1 | ||
| 198 | didUnstuff1: | ||
| 199 | subi cnt, 1 ;1 [20] | ||
| 200 | brcs overflow ;1 [21] loop control | ||
| 201 | eor x2, x1 ;1 [22] | ||
| 202 | bst x2, USBMINUS;1 [23] | ||
| 203 | bld shift, 2 ;1 [24] | ||
| 204 | in x2, USBIN ;1 [25] <-- sample bit 3 (or possibly bit 2 stuffed) | ||
| 205 | andi shift, 0xe7 ;1 [26] | ||
| 206 | breq unstuff2 ;1 [27] | ||
| 207 | didUnstuff2: | ||
| 208 | eor x1, x2 ;1 [28] | ||
| 209 | bst x1, USBMINUS;1 [29] | ||
| 210 | bld shift, 3 ;1 [30] | ||
| 211 | didUnstuff3: | ||
| 212 | andi shift, 0xcf ;1 [31] | ||
| 213 | breq unstuff3 ;1 [32] | ||
| 214 | in x1, USBIN ;1 [33] <-- sample bit 4 | ||
| 215 | eor x2, x1 ;1 [34] | ||
| 216 | bst x2, USBMINUS;1 [35] | ||
| 217 | bld shift, 4 ;1 [36] | ||
| 218 | didUnstuff4: | ||
| 219 | andi shift, 0x9f ;1 [37] | ||
| 220 | breq unstuff4 ;1 [38] | ||
| 221 | nop2 ;2 [40] | ||
| 222 | in x2, USBIN ;1 [41] <-- sample bit 5 | ||
| 223 | eor x1, x2 ;1 [42] | ||
| 224 | bst x1, USBMINUS;1 [43] | ||
| 225 | bld shift, 5 ;1 [44] | ||
| 226 | didUnstuff5: | ||
| 227 | andi shift, 0x3f ;1 [45] | ||
| 228 | breq unstuff5 ;1 [46] | ||
| 229 | nop2 ;2 [48] | ||
| 230 | in x1, USBIN ;1 [49] <-- sample bit 6 | ||
| 231 | eor x2, x1 ;1 [50] | ||
| 232 | bst x2, USBMINUS;1 [51] | ||
| 233 | bld shift, 6 ;1 [52] | ||
| 234 | didUnstuff6: | ||
| 235 | cpi shift, 0x02 ;1 [53] | ||
| 236 | brlo unstuff6 ;1 [54] | ||
| 237 | nop2 ;2 [56] | ||
| 238 | in x2, USBIN ;1 [57] <-- sample bit 7 | ||
| 239 | eor x1, x2 ;1 [58] | ||
| 240 | bst x1, USBMINUS;1 [59] | ||
| 241 | bld shift, 7 ;1 [60] | ||
| 242 | didUnstuff7: | ||
| 243 | cpi shift, 0x04 ;1 [61] | ||
| 244 | brsh rxLoop ;2 [63] loop control | ||
| 245 | unstuff7: | ||
| 246 | andi x3, ~0x80 ;1 [63] | ||
| 247 | ori shift, 0x80 ;1 [64] | ||
| 248 | in x2, USBIN ;1 [65] <-- sample stuffed bit 7 | ||
| 249 | nop ;1 [66] | ||
| 250 | rjmp didUnstuff7 ;2 [68] | ||
| 251 | |||
| 252 | macro POP_STANDARD ; 12 cycles | ||
| 253 | pop cnt | ||
| 254 | pop x3 | ||
| 255 | pop x2 | ||
| 256 | pop x1 | ||
| 257 | pop shift | ||
| 258 | pop YH | ||
| 259 | endm | ||
| 260 | macro POP_RETI ; 5 cycles | ||
| 261 | pop YL | ||
| 262 | out SREG, YL | ||
| 263 | pop YL | ||
| 264 | endm | ||
| 265 | |||
| 266 | #include "asmcommon.inc" | ||
| 267 | |||
| 268 | ;---------------------------------------------------------------------------- | ||
| 269 | ; Transmitting data | ||
| 270 | ;---------------------------------------------------------------------------- | ||
| 271 | |||
| 272 | txByteLoop: | ||
| 273 | txBitloop: | ||
| 274 | stuffN1Delay: ; [03] | ||
| 275 | ror shift ;[-5] [11] [59] | ||
| 276 | brcc doExorN1 ;[-4] [60] | ||
| 277 | subi x4, 1 ;[-3] | ||
| 278 | brne commonN1 ;[-2] | ||
| 279 | lsl shift ;[-1] compensate ror after rjmp stuffDelay | ||
| 280 | nop ;[00] stuffing consists of just waiting 8 cycles | ||
| 281 | rjmp stuffN1Delay ;[01] after ror, C bit is reliably clear | ||
| 282 | |||
| 283 | sendNakAndReti: ;0 [-19] 19 cycles until SOP | ||
| 284 | ldi x3, USBPID_NAK ;1 [-18] | ||
| 285 | rjmp usbSendX3 ;2 [-16] | ||
| 286 | sendAckAndReti: ;0 [-19] 19 cycles until SOP | ||
| 287 | ldi x3, USBPID_ACK ;1 [-18] | ||
| 288 | rjmp usbSendX3 ;2 [-16] | ||
| 289 | sendCntAndReti: ;0 [-17] 17 cycles until SOP | ||
| 290 | mov x3, cnt ;1 [-16] | ||
| 291 | usbSendX3: ;0 [-16] | ||
| 292 | ldi YL, 20 ;1 [-15] 'x3' is R20 | ||
| 293 | ldi YH, 0 ;1 [-14] | ||
| 294 | ldi cnt, 2 ;1 [-13] | ||
| 295 | ; rjmp usbSendAndReti fallthrough | ||
| 296 | |||
| 297 | ; USB spec says: | ||
| 298 | ; idle = J | ||
| 299 | ; J = (D+ = 0), (D- = 1) or USBOUT = 0x01 | ||
| 300 | ; K = (D+ = 1), (D- = 0) or USBOUT = 0x02 | ||
| 301 | ; Spec allows 7.5 bit times from EOP to SOP for replies (= 60 cycles) | ||
| 302 | |||
| 303 | ;usbSend: | ||
| 304 | ;pointer to data in 'Y' | ||
| 305 | ;number of bytes in 'cnt' -- including sync byte | ||
| 306 | ;uses: x1...x2, x4, shift, cnt, Y [x1 = mirror USBOUT, x2 = USBMASK, x4 = bitstuff cnt] | ||
| 307 | ;Numbers in brackets are time since first bit of sync pattern is sent (start of instruction) | ||
| 308 | usbSendAndReti: | ||
| 309 | in x2, USBDDR ;[-12] 12 cycles until SOP | ||
| 310 | ori x2, USBMASK ;[-11] | ||
| 311 | sbi USBOUT, USBMINUS ;[-10] prepare idle state; D+ and D- must have been 0 (no pullups) | ||
| 312 | out USBDDR, x2 ;[-8] <--- acquire bus | ||
| 313 | in x1, USBOUT ;[-7] port mirror for tx loop | ||
| 314 | ldi shift, 0x40 ;[-6] sync byte is first byte sent (we enter loop after ror) | ||
| 315 | ldi x2, USBMASK ;[-5] | ||
| 316 | push x4 ;[-4] | ||
| 317 | doExorN1: | ||
| 318 | eor x1, x2 ;[-2] [06] [62] | ||
| 319 | ldi x4, 6 ;[-1] [07] [63] | ||
| 320 | commonN1: | ||
| 321 | stuffN2Delay: | ||
| 322 | out USBOUT, x1 ;[00] [08] [64] <--- set bit | ||
| 323 | ror shift ;[01] | ||
| 324 | brcc doExorN2 ;[02] | ||
| 325 | subi x4, 1 ;[03] | ||
| 326 | brne commonN2 ;[04] | ||
| 327 | lsl shift ;[05] compensate ror after rjmp stuffDelay | ||
| 328 | rjmp stuffN2Delay ;[06] after ror, C bit is reliably clear | ||
| 329 | doExorN2: | ||
| 330 | eor x1, x2 ;[04] [12] | ||
| 331 | ldi x4, 6 ;[05] [13] | ||
| 332 | commonN2: | ||
| 333 | nop ;[06] [14] | ||
| 334 | subi cnt, 171 ;[07] [15] trick: (3 * 171) & 0xff = 1 | ||
| 335 | out USBOUT, x1 ;[08] [16] <--- set bit | ||
| 336 | brcs txBitloop ;[09] [25] [41] | ||
| 337 | |||
| 338 | stuff6Delay: | ||
| 339 | ror shift ;[42] [50] | ||
| 340 | brcc doExor6 ;[43] | ||
| 341 | subi x4, 1 ;[44] | ||
| 342 | brne common6 ;[45] | ||
| 343 | lsl shift ;[46] compensate ror after rjmp stuffDelay | ||
| 344 | nop ;[47] stuffing consists of just waiting 8 cycles | ||
| 345 | rjmp stuff6Delay ;[48] after ror, C bit is reliably clear | ||
| 346 | doExor6: | ||
| 347 | eor x1, x2 ;[45] [53] | ||
| 348 | ldi x4, 6 ;[46] | ||
| 349 | common6: | ||
| 350 | stuff7Delay: | ||
| 351 | ror shift ;[47] [55] | ||
| 352 | out USBOUT, x1 ;[48] <--- set bit | ||
| 353 | brcc doExor7 ;[49] | ||
| 354 | subi x4, 1 ;[50] | ||
| 355 | brne common7 ;[51] | ||
| 356 | lsl shift ;[52] compensate ror after rjmp stuffDelay | ||
| 357 | rjmp stuff7Delay ;[53] after ror, C bit is reliably clear | ||
| 358 | doExor7: | ||
| 359 | eor x1, x2 ;[51] [59] | ||
| 360 | ldi x4, 6 ;[52] | ||
| 361 | common7: | ||
| 362 | ld shift, y+ ;[53] | ||
| 363 | tst cnt ;[55] | ||
| 364 | out USBOUT, x1 ;[56] <--- set bit | ||
| 365 | brne txByteLoop ;[57] | ||
| 366 | |||
| 367 | ;make SE0: | ||
| 368 | cbr x1, USBMASK ;[58] prepare SE0 [spec says EOP may be 15 to 18 cycles] | ||
| 369 | lds x2, usbNewDeviceAddr;[59] | ||
| 370 | lsl x2 ;[61] we compare with left shifted address | ||
| 371 | subi YL, 2 + 20 ;[62] Only assign address on data packets, not ACK/NAK in x3 | ||
| 372 | sbci YH, 0 ;[63] | ||
| 373 | out USBOUT, x1 ;[00] <-- out SE0 -- from now 2 bits = 16 cycles until bus idle | ||
| 374 | ;2006-03-06: moved transfer of new address to usbDeviceAddr from C-Code to asm: | ||
| 375 | ;set address only after data packet was sent, not after handshake | ||
| 376 | breq skipAddrAssign ;[01] | ||
| 377 | sts usbDeviceAddr, x2 ; if not skipped: SE0 is one cycle longer | ||
| 378 | skipAddrAssign: | ||
| 379 | ;end of usbDeviceAddress transfer | ||
| 380 | ldi x2, 1<<USB_INTR_PENDING_BIT;[03] int0 occurred during TX -- clear pending flag | ||
| 381 | USB_STORE_PENDING(x2) ;[04] | ||
| 382 | ori x1, USBIDLE ;[05] | ||
| 383 | in x2, USBDDR ;[06] | ||
| 384 | cbr x2, USBMASK ;[07] set both pins to input | ||
| 385 | mov x3, x1 ;[08] | ||
| 386 | cbr x3, USBMASK ;[09] configure no pullup on both pins | ||
| 387 | pop x4 ;[10] | ||
| 388 | nop2 ;[12] | ||
| 389 | nop2 ;[14] | ||
| 390 | out USBOUT, x1 ;[16] <-- out J (idle) -- end of SE0 (EOP signal) | ||
| 391 | out USBDDR, x2 ;[17] <-- release bus now | ||
| 392 | out USBOUT, x3 ;[18] <-- ensure no pull-up resistors are active | ||
| 393 | rjmp doReturn | ||
