cleanup CIC asm code
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Maximilian Rehkopf
parent
b2a02a6081
commit
42082bd2ac
@ -1,8 +1,59 @@
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#include <p12f629.inc>
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processor p12f629
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; ---------------------------------------------------------------------
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; SNES CIC clone for PIC Microcontroller (key mode only)
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;
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; Copyright (C) 2010 by Maximilian Rehkopf <otakon@gmx.net>
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;
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; This program is free software; you can redistribute it and/or modify
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; it under the terms of the GNU General Public License as published by
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; the Free Software Foundation; version 2 of the License only.
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;
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; This program is distributed in the hope that it will be useful,
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; but WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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; GNU General Public License for more details.
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;
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; You should have received a copy of the GNU General Public License
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; along with this program; if not, write to the Free Software
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; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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;
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; ---------------------------------------------------------------------
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;
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; pin configuration: (cartridge pin) [key CIC pin]
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;
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; ,---_---.
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; +5V (27,58) [16] |1 8| GND (5,36) [8]
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; CIC clk (56) [6] |2 7| CIC data i/o 0 (55) [1]
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; status out |3 6| CIC data i/o 1 (24) [2]
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; nc |4 5| CIC slave reset (25) [7]
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; `-------'
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;
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;
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; status out can be connected to a LED. It indicates:
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;
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; state | output
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; -------------------------+--------------------
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; OK (normal operation) | high
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; error (unlock failed) | alternating @~2.5Hz
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;
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; memory usage:
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;
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; 0x20 buffer for seed calc and transfer
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; 0x21 - 0x2f seed area (lock seed)
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; 0x30 buffer for seed calc
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; 0x31 - 0x3f seed area (key seed; 0x31 filled in by lock)
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; 0x40 - 0x41 buffer for seed calc
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; 0x4d buffer for eeprom access
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; 0x4e loop variable for longwait
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; 0x4f loop variable for wait
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;
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; ---------------------------------------------------------------------
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; -----------------------------------------------------------------------
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__CONFIG _EC_OSC & _WDT_OFF & _PWRTE_OFF & _MCLRE_OFF & _CP_OFF & _CPD_OFF; & _BOD_ON & _IESO_ON & _FCMEN_ON
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__CONFIG _EC_OSC & _WDT_OFF & _PWRTE_OFF & _MCLRE_OFF & _CP_OFF & _CPD_OFF
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; -----------------------------------------------------------------------
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; code memory
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@ -11,19 +62,19 @@ processor p12f629
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nop
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nop
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goto init
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;"isr"
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isr
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org 0x0004
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bcf INTCON, 1 ; clear interrupt cause
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bcf GPIO, 0
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bcf GPIO, 1
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bsf GPIO, 4
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bsf GPIO, 4 ; LED on
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nop
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nop
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nop
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nop
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nop
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nop
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bsf INTCON, 7 ; re-enable interrupts (for the ISR will replace the main)
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bsf INTCON, 7 ; re-enable interrupts (ISR will continue as main)
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goto main
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init
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org 0x0010
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@ -31,7 +82,7 @@ init
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clrf GPIO
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movlw 0x07 ; GPIO2..0 are digital I/O (not connected to comparator)
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movwf CMCON
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movlw 0x90 ; Enable interrupts + enable INT
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movlw 0x90 ; global enable interrupts + enable external interrupt
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movwf INTCON
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banksel TRISIO
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movlw 0x2d ; in out in in out in
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@ -39,15 +90,16 @@ init
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movlw 0x80 ; 0x00 for pullups
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movwf OPTION_REG
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banksel GPIO
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bsf GPIO, 0x0
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bsf GPIO, 4 ; LED on
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idle
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goto idle ; wait for interrupt from lock
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idle goto idle
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main
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banksel TRISIO
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bsf TRISIO, 0
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bcf TRISIO, 1
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banksel GPIO
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;--------INIT KEY SEED--------
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; --------INIT LOCK SEED (what the lock sends)--------
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movlw 0xb
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movwf 0x21
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movlw 0x1
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@ -79,11 +131,11 @@ main
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movlw 0x8
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movwf 0x2f
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;--------INIT LOCK SEED--------
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banksel EEADR
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clrf EEADR
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bsf EECON1, RD
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movf EEDAT, w
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; --------INIT KEY SEED (what we must send)--------
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banksel EEADR ; D/F411 and D/F413
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clrf EEADR ; differ in 2nd seed nibble
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bsf EECON1, RD ; of key stream,
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movf EEDAT, w ; restore saved nibble from EEPROM
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banksel GPIO
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movwf 0x32
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movlw 0xa
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@ -112,13 +164,14 @@ main
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movlw 0xc
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movwf 0x3f
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;--------Main loop--------
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; --------wait for stream ID--------
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movlw 0xb5
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call wait
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clrf 0x31 ; clear lock stream ID
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; --------lock sends stream ID. 15 cycles per bit--------
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; bsf GPIO, 0
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; bcf GPIO, 0
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; bsf GPIO, 0 ; (debug marker)
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; bcf GPIO, 0 ;
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btfsc GPIO, 0 ; check stream ID bit
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bsf 0x31, 3 ; copy to lock seed
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movlw 0x2 ; wait=3*W+5
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@ -153,29 +206,15 @@ main
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bsf TRISIO, 1
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banksel GPIO
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nop
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movlw 0x27 ; "wait" 1
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call wait ; wait 121
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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nop
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movlw 0x22 ; "wait" 1
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call wait ; wait 107
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nop
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nop
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; --------main loop--------
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loop
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movlw 0x1
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loop0
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addlw 0x30 ; key stream (what we thought was the lock stream...)
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addlw 0x30 ; key stream
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movwf FSR ; store in index reg
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loop1
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movf INDF, w ; load seed value
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@ -183,7 +222,7 @@ loop1
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bcf 0x20, 1 ; clear bit 1
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btfsc 0x20, 0 ; copy from bit 0
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bsf 0x20, 1 ; (if set)
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bsf 0x20, 4 ; status pin
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bsf 0x20, 4 ; LED on
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movf 0x20, w
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movwf GPIO
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nop
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@ -192,10 +231,10 @@ loop1
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movlw 0x16
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call wait
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nop
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btfsc GPIO, 0
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goto die
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btfsc GPIO, 1
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btfsc GPIO, 0 ; both pins must be low...
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goto die
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btfsc GPIO, 1 ; ...when no bit transfer takes place
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goto die ; if not -> lock cic error state -> die
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incf FSR, f ; next one
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movlw 0xf
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andwf FSR, w
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@ -227,9 +266,9 @@ swapskip
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goto loop0
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goto loop
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;--------mangle--------
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;this is damn tight because the PIC has no convenient instructions at all
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;
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; --------calculate new seeds--------
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; had to be unrolled because PIC has an inefficient way of handling
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; indirect access, no post increment, etc.
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mangle
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call mangle_lock
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nop
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@ -308,7 +347,7 @@ mangle_key_withoutskip
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movf 0x2e, w ;
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addlw 0x1 ; inc
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addwf 0x2f, f ; add to 2f
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;60
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movf 0x20, w ; restore original 0xf
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andlw 0xf
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addlw 0xf
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@ -385,7 +424,7 @@ mangle_key_withskip
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movf 0x2e, w ;
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addlw 0x1 ; inc
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addwf 0x2f, f ; add to 2f
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;64
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movf 0x20, w ; restore original 0xf
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andlw 0xf
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addlw 0xf
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@ -613,10 +652,10 @@ die
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btfsc 0x4d, 0
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goto die_reg_6
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die_reg_9
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movlw 0x9
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movlw 0x9 ; died with PAL, fall back to NTSC
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goto die_reg_cont
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die_reg_6
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movlw 0x6
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movlw 0x6 ; died with NTSC, fall back to PAL
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die_reg_cont
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banksel EEADR
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movwf EEDAT
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@ -639,12 +678,12 @@ die_intloop
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die_blink
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clrw
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call longwait
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bsf GPIO, 4
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call longwait
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bcf GPIO, 4
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call longwait
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bsf GPIO, 4
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goto die_blink
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; -----------------------------------------------------------------------
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; eeprom memory
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DEEPROM CODE
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de 0x09
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de 0x09 ; D411 (NTSC)
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end
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