#include <REG51F380.H>

;-------------------------------------------------------------------------------------------------------------------;
;CONSTANT DEFINES FOR CHAR_NUM AND CHAR_STATE
;-------------------------------------------------------------------------------------------------------------------;
CHAR_0          EQU 0C0H                ;DEFINE CHARS FOR 8BITSEG
CHAR_1          EQU 0F9H
CHAR_2          EQU 0A4H
CHAR_3          EQU 0B0H
CHAR_4          EQU 099H
CHAR_5          EQU 092H
CHAR_6          EQU 082H
CHAR_7          EQU 0F8H
CHAR_8          EQU 080H
CHAR_9          EQU 090H

CHAR_L EQU 0C7H
CHAR_F EQU 8EH
;-------------------------------------------------------------------------------------------------------------------;
;       ESTADOS
;-------------------------------------------------------------------------------------------------------------------;
S_RECOVER EQU 0
S_LOCKED EQU 1
S_OPEN EQU 2
S_ENCRYPT EQU 3
S_DESENCRYPT EQU 4
S_FAIL EQU 5

MASQ EQU 0A2H
MASQ_2 EQU 0FH
KEYLEN EQU 4
ERRO EQU 0
;-------------------------------------------------------------------------------------------------
;       HARDWARE ASSIGNMENTS
;-------------------------------------------------------------------------------------------------
KSET EQU P0.6
KLOAD EQU P0.7
TB EQU P2.7
;-------------------------------------------------------------------------------------------------
;       VARIABLES
;-------------------------------------------------------------------------------------------------
USER_KEY XDATA 70H
SEC_KEY IDATA 60H

DSEG AT 40H
    STATE: DS 1
    N_STATE: DS 1

BSEG AT 0H      ;comeca na area enderecavel ao bit - 20h
    VALID: DBIT 1
    RECOVERY: DBIT 1
    FECHADO: DBIT 1

CSEG AT 600H        ;caracteres segmento 8bits
    DIGITS_TABLE:
        DB CHAR_0, CHAR_1, CHAR_2, CHAR_3, CHAR_4, CHAR_5, CHAR_6, CHAR_7, CHAR_8, CHAR_9   ;0-9 CHAR_L, CHAR_F

CSEG AT 0H
    JMP RESET
;-------------------------------------------------------------------------------------------------
;       INIT_DEVICE
;-------------------------------------------------------------------------------------------------
PCA_Init:
    MOV  PCA0MD,    #000h
    RET
Port_IO_Init:
    MOV  XBR1,      #040h
    RET
TIMER_INIT:
    MOV FLSCL, #90H
    MOV CLKSEL, #30H
    RET
Init_Device:
    lcall PCA_Init
    lcall Port_IO_Init
    LCALL TIMER_INIT
    ret
;-------------------------------------------------------------------------------------------------
;       RESET
;-------------------------------------------------------------------------------------------------
RESET:
    ACALL Init_Device
    SETB KSET               ;ATIVAR BOTOES
    SETB KLOAD
    SETB TB
    SETB RECOVERY
    CLR FECHADO
    CLR VALID
    MOV R0, #SEC_KEY
    MOV R1, #USER_KEY
    MOV R3, #0H
    MOV A, #0H
    MOV B, #0H
    MOV ERRO, #0
    MOV STATE, #S_RECOVER
    MOV N_STATE, #S_RECOVER
    JMP STATE_MACHINE
;-------------------------------------------------------------------------------------------------
;       STATE MACHINE
;-------------------------------------------------------------------------------------------------
STATE_MACHINE:
    MOV STATE, N_STATE
    MOV A, STATE
    RL A
    MOV DPTR, #JMP_TABLE
    JMP @A+DPTR
JMP_TABLE:
    AJMP RECOVER
    AJMP LOCKED
    AJMP OPEN
    AJMP ENCRYPT
    AJMP DESENCRYPT
    AJMP FAIL

;-------------------------------------------------------------------------------------------------
;       STATE RECOVERY + STATE LOCKED ----USAM O MESMO CODIGO
;-------------------------------------------------------------------------------------------------
START:              ;aguarda que o utilizador carregue no kset para continuar o programa
    JB KSET, START
    JNB KSET, $
    RET

RECOVER:
    JMP DISPCHARS
LOCKED:
    MOV R1, #USER_KEY
    MOV P2, #CHAR_L
    CLR TB
    ACALL START

;-------------------------------------------------------------------------------------------------
;       8 BIT SEGMENT UPDATE_DISPLAY AND INCREMENT
;-------------------------------------------------------------------------------------------------
DISPCHARS:
    MOV DPTR, #DIGITS_TABLE
    MOV R3, #0H
UPDATE_DISPLAY:
    MOV A, R3
    MOVC A, @A+DPTR
    MOV P2, A
    JNB FECHADO, BUTTONS
    CLR TB
BUTTONS:
    JNB KLOAD, LOAD_KEY
    JB KSET, BUTTONS
INCREMENT:
    JNB KSET, $
    INC R3
    CJNE R3, #10, UPDATE_DISPLAY
    JMP DISPCHARS

;-------------------------------------------------------------------------------------------------
;       SALVAGUARDA O VALOR ESCOLHIDO
;-------------------------------------------------------------------------------------------------
LOAD_KEY:
    MOV A, R3
    MOVX @R1, A
    INC R1
    MOV A, R1
    ANL A, #MASQ_2
    CJNE A, #KEYLEN, DISPCHARS
AUX:
    JB RECOVERY, RELOAD_KEY
    JNB FECHADO, AUX
    MOV N_STATE, #S_DESENCRYPT
    JMP STATE_MACHINE

RELOAD_KEY:
    CLR RECOVERY
    MOV N_STATE, #S_ENCRYPT
    JMP STATE_MACHINE

;-------------------------------------------------------------------------------------------------
;       STATE DESENCRYPT
;-------------------------------------------------------------------------------------------------
DESENCRYPT:
    MOV R0, #SEC_KEY
    MOV R1, #USER_KEY
    MOV R3, #0H
    MOV N_STATE, #S_FAIL
    CLR VALID
DESENCRYPT_LOOP:
    MOV A, @R0
    XRL A, #MASQ
    MOV B, A
    MOVX A, @R1
    CJNE A, B, STATE_MACHINE
    INC R0
    INC R1
    INC R3
    CJNE R3, #KEYLEN, DESENCRYPT_LOOP
    SETB VALID
    SETB TB
    CLR FECHADO
    MOV N_STATE, #S_OPEN
    JMP STATE_MACHINE

;-------------------------------------------------------------------------------------------------
;       STATE ENCRYPT
;-------------------------------------------------------------------------------------------------
ENCRYPT:
    MOV R0, #SEC_KEY
    MOV R1, #USER_KEY
    MOV R3, #0H
ENCRYPT_LOOP:
    MOVX A, @R1
    XRL A, #MASQ
    MOV @R0, A
    INC R3
    INC R1
    INC R0
    CJNE R3, #KEYLEN, ENCRYPT_LOOP
    MOV N_STATE, #S_LOCKED
    SETB FECHADO
    JMP STATE_MACHINE

;-------------------------------------------------------------------------------------------------
;       STATE FAIL
;-------------------------------------------------------------------------------------------------
FAIL:
    MOV P2, #CHAR_F
    CLR TB      ;OU PODEMOS IGNORAR O TB NO CASO DE BLOQUEIO?
    INC ERRO
    ;engodo do timer
    JMP FAIL

    MOV N_STATE, #S_LOCKED
    JMP STATE_MACHINE
;-------------------------------------------------------------------------------------------------
;       STATE OPEN
;-------------------------------------------------------------------------------------------------
OPEN:
    MOV P2, #CHAR_0
    JNB KLOAD, OPEN
    JB KSET, OPEN
    JNB KSET, $

NEW_PASSWORD:

CLOSE:
    JNB KLOAD, $
    MOV N_STATE, #S_LOCKED
    JMP STATE_MACHINE

END