- used wrong name in copy -- fixed this

1 files changed, 427 insertions, 0 deletions

diff --git a/usbdrv/usbdrvasm12.inc b/usbdrv/usbdrvasm12.inc
new file mode 100644
index 0000000..32c30c7
--- /dev/null
+++ b/usbdrv/usbdrvasm12.inc
@@ -0,0 +1,427 @@
+/* Name: usbdrvasm12.inc
+ * Project: AVR USB driver
+ * 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) or proprietary (CommercialLicense.txt)
+ * This Revision: $Id$
+ */
+
+/* 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
+;first part has no timeout because it waits for IDLE or SE1 (== disconnected)
+waitForJ:
+    sbis    USBIN, USBMINUS ;1 [40] wait for D- == 1
+    rjmp    waitForJ        ;2
+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 */
+    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
+;----------------------------------------------------------------------------
+
+bitstuff0:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    ldi     x2, 0           ;1
+    out     USBOUT, x1      ;1 <-- out
+    rjmp    didStuff0       ;2 branch back 2 cycles earlier
+bitstuff1:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff1       ;2 we know that C is clear, jump back to do OUT and ror 0 into x2
+bitstuff2:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff2       ;2 jump back 4 cycles earlier and do out and ror 0 into x2
+bitstuff3:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff3       ;2 jump back earlier and ror 0 into x2
+bitstuff4:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    ldi     x2, 0           ;1
+    out     USBOUT, x1      ;1 <-- out
+    rjmp    didStuff4       ;2 jump back 2 cycles earlier
+
+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...x4, shift, cnt, Y
+;Numbers in brackets are time since first bit of sync pattern is sent
+usbSendAndReti:             ;0 [-13] timing: 13 cycles until SOP
+    in      x2, USBDDR      ;1 [-12]
+    ori     x2, USBMASK     ;1 [-11]
+    sbi     USBOUT, USBMINUS;2 [-9] prepare idle state; D+ and D- must have been 0 (no pullups)
+    in      x1, USBOUT      ;1 [-8] port mirror for tx loop
+    out     USBDDR, x2      ;1 [-7] <- acquire bus
+; need not init x2 (bitstuff history) because sync starts with 0
+    push    x4              ;2 [-5]
+    ldi     x4, USBMASK     ;1 [-4] exor mask
+    ldi     shift, 0x80     ;1 [-3] sync byte is first byte sent
+txLoop:                     ;       [62]
+    sbrs    shift, 0        ;1 [-2] [62]
+    eor     x1, x4          ;1 [-1] [63]
+    out     USBOUT, x1      ;1 [0] <-- out bit 0
+    ror     shift           ;1 [1]
+    ror     x2              ;1 [2]
+didStuff0:
+    cpi     x2, 0xfc        ;1 [3]
+    brsh    bitstuff0       ;1 [4]
+    sbrs    shift, 0        ;1 [5]
+    eor     x1, x4          ;1 [6]
+    ror     shift           ;1 [7]
+didStuff1:
+    out     USBOUT, x1      ;1 [8] <-- out bit 1
+    ror     x2              ;1 [9]
+    cpi     x2, 0xfc        ;1 [10]
+    brsh    bitstuff1       ;1 [11]
+    sbrs    shift, 0        ;1 [12]
+    eor     x1, x4          ;1 [13]
+    ror     shift           ;1 [14]
+didStuff2:
+    ror     x2              ;1 [15]
+    out     USBOUT, x1      ;1 [16] <-- out bit 2
+    cpi     x2, 0xfc        ;1 [17]
+    brsh    bitstuff2       ;1 [18]
+    sbrs    shift, 0        ;1 [19]
+    eor     x1, x4          ;1 [20]
+    ror     shift           ;1 [21]
+didStuff3:
+    ror     x2              ;1 [22]
+    cpi     x2, 0xfc        ;1 [23]
+    out     USBOUT, x1      ;1 [24] <-- out bit 3
+    brsh    bitstuff3       ;1 [25]
+    nop2                    ;2 [27]
+    ld      x3, y+          ;2 [29]
+    sbrs    shift, 0        ;1 [30]
+    eor     x1, x4          ;1 [31]
+    out     USBOUT, x1      ;1 [32] <-- out bit 4
+    ror     shift           ;1 [33]
+    ror     x2              ;1 [34]
+didStuff4:
+    cpi     x2, 0xfc        ;1 [35]
+    brsh    bitstuff4       ;1 [36]
+    sbrs    shift, 0        ;1 [37]
+    eor     x1, x4          ;1 [38]
+    ror     shift           ;1 [39]
+didStuff5:
+    out     USBOUT, x1      ;1 [40] <-- out bit 5
+    ror     x2              ;1 [41]
+    cpi     x2, 0xfc        ;1 [42]
+    brsh    bitstuff5       ;1 [43]
+    sbrs    shift, 0        ;1 [44]
+    eor     x1, x4          ;1 [45]
+    ror     shift           ;1 [46]
+didStuff6:
+    ror     x2              ;1 [47]
+    out     USBOUT, x1      ;1 [48] <-- out bit 6
+    cpi     x2, 0xfc        ;1 [49]
+    brsh    bitstuff6       ;1 [50]
+    sbrs    shift, 0        ;1 [51]
+    eor     x1, x4          ;1 [52]
+    ror     shift           ;1 [53]
+didStuff7:
+    ror     x2              ;1 [54]
+    cpi     x2, 0xfc        ;1 [55]
+    out     USBOUT, x1      ;1 [56] <-- out bit 7
+    brsh    bitstuff7       ;1 [57]
+    mov     shift, x3       ;1 [58]
+    dec     cnt             ;1 [59]
+    brne    txLoop          ;1/2 [60/61]
+;make SE0:
+    cbr     x1, USBMASK     ;1 [61] prepare SE0 [spec says EOP may be 15 to 18 cycles]
+    pop     x4              ;2 [63]
+;brackets are cycles from start of SE0 now
+    out     USBOUT, x1      ;1 [0] <-- 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
+    lds     x2, usbNewDeviceAddr;2 [2]
+    lsl     x2;             ;1 [3] we compare with left shifted address
+    subi    YL, 20 + 2      ;1 [4] Only assign address on data packets, not ACK/NAK in x3
+    sbci    YH, 0           ;1 [5]
+    breq    skipAddrAssign  ;2 [7]
+    sts     usbDeviceAddr, x2; if not skipped: SE0 is one cycle longer
+skipAddrAssign:
+;end of usbDeviceAddress transfer
+    ldi     x2, 1<<USB_INTR_PENDING_BIT;1 [8] int0 occurred during TX -- clear pending flag
+    USB_STORE_PENDING(x2)   ;1 [9]
+    ori     x1, USBIDLE     ;1 [10]
+    in      x2, USBDDR      ;1 [11]
+    cbr     x2, USBMASK     ;1 [12] set both pins to input
+    mov     x3, x1          ;1 [13]
+    cbr     x3, USBMASK     ;1 [14] configure no pullup on both pins
+    out     USBOUT, x1      ;1 [15] <-- out J (idle) -- end of SE0 (EOP signal)
+    out     USBDDR, x2      ;1 [16] <-- release bus now
+    out     USBOUT, x3      ;1 [17] <-- ensure no pull-up resistors are active
+    rjmp    doReturn
+
+bitstuff5:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff5       ;2 same trick as in bitstuff1...
+bitstuff6:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff6       ;2 same trick as above...
+bitstuff7:                  ;1 (for branch taken)
+    eor     x1, x4          ;1
+    rjmp    didStuff7       ;2 same trick as above...
+