; Justice Unlimited Gadget Microcode
; (C) 2004 Nathan (Acorn) Pooley 
;
; gutil.inc
;
;@DOC@ Various utility functions
;

;############################################
;############### WAIT #######################
;############################################

wait_1sec:
    rcall   wait_333ms

wait_666ms:
    rcall   wait_333ms

wait_333ms:
    movlw   228

    ;
    ; wait approx 12 cycles * w = 1.464ms * w
    ;
wait:
    movwf   v_wait_cnt
wait_loop:
    rcall   time
    decfsz  v_wait_cnt
    bra     wait_loop

    return

;############################################
;############### TABLE SETUP ################
;############################################

    ;
    ; setup to read from program memory
    ;
setup_progread:
    bcf     b_cfgs      ; access program mem (not config regs)
    bsf     b_eepgd     ; access program mem (not eeprom)
    clrf    TBLPTRU     ; zero the pointer
    clrf    TBLPTRH     ; zero the pointer
    clrf    TBLPTRL     ; zero the pointer
    return

;############################################
;############### PUT NUMBER #################
;############################################

    ;
    ; draw 2 digit number (decimal value)
    ;    w should hold number (must be less than 100)
    ;
putnum_2d:
    clrf    v_num_hi
    movwf   v_num_lo
    bsf     b_num_started
    bra     putnum_10

    ;
    ; draw byte (decimal value)
    ;    w should hold number
    ;
putnum_w:
    clrf    v_num_hi
    movwf   v_num_lo

    ;
    ; draw number (decimal value)
    ;    v_num_lo, v_num_hi should hold number
    ;
putnum:
    bcf     b_num_started   ; clear this until 1st nonzero digit

    movlw   HIGH 10000      ; 10000 digit
    movwf   v_num_digit_hi
    movlw   LOW 10000
    movwf   v_num_digit_lo
    rcall   putnum_digit

    movlw   HIGH 1000       ; 1000 digit
    movwf   v_num_digit_hi
    movlw   LOW 1000
    movwf   v_num_digit_lo
    rcall   putnum_digit

    clrf    v_num_digit_hi  ; 100 digit
    movlw   100
    movwf   v_num_digit_lo
    rcall   putnum_digit

putnum_10:
    clrf    v_num_digit_hi
    movlw   10              ; 10 digit
    movwf   v_num_digit_lo
    rcall   putnum_digit

    bsf     b_num_started   ; draw 1 digit even if zero
    movlw   1               ; 1 digit
    movwf   v_num_digit_lo
    bra     putnum_digit

    ; DONE - returns to caller


    ;
    ; draw digit (if not a leading 0)
    ; remove that digit from v_num_lo, v_num_hi
    ; v_num_digit_lo, v_num_digit_hi indicate which digit
    ;
putnum_digit:
    setf    v_tmp

    ;
    ; find value of digit (into v_tmp)
    ;
putnum_loop:
    incf    v_tmp,f             ; find digit (starts at -1)
    movf    v_num_digit_lo,w
    subwf   v_num_lo,f
    movf    v_num_digit_hi,w
    subwfb  v_num_hi,f
    bc      putnum_loop         ; cross 0?

    ;
    ; add digit back into number 
    ;
    movf    v_num_digit_lo,w
    addwf   v_num_lo,f
    movf    v_num_digit_hi,w
    addwfc  v_num_hi,f

    ;
    ; print a digit
    ;
putnum_sub:
    movf    v_tmp,w
    btfss   STATUS,Z
    bsf     b_num_started   ; if nonzero, it is started
    addlw   '0'
    btfsc   b_num_started
    bra     putc_raw        ; draw digit & return to putnum
    return

;############################################
;############### PUT TIME ###################
;############################################

    ;
    ; draw a time value
    ;   w            - holds hours
    ;   v_ptime_min  - holds minutes
    ;   v_ptime_sec  - holds seconds
    ;
put_time:
    rcall   putnum_w        ; hours
    movlw   ':'
    rcall   putc_raw
    movf    v_ptime_min,w
    rcall   putnum_2d       ; minutes
    movlw   ':'
    rcall   putc_raw
    movf    v_ptime_sec,w
    bra     putnum_2d       ; seconds

    ; DONE - return to caller


;############################################
;############### PARSE NUM ##################
;############################################
    ;
    ; parse decimal number from entry buf 
    ;  put result in v_num_lo, v_num_hi
    ;
parse_dec:
    lfsr    FSR0,BUF_ENTRY
parse_dec_frombuf:
    clrf    v_num_lo
    clrf    v_num_hi
    clrf    v_num_bits

parse_dec_loop:
    ;
    ; get next decimal digit
    ;
    movf    POSTINC0,w
    bz      parse_end
    addlw   LOW -'0'        ; is digit 0-9?
    bn      parse_bad_digit
    movwf   v_tmp           ; store digit in v_tmp
    addlw   LOW -10
    bnn     parse_bad_digit

    ;
    ; multiply by 10
    ;
    rcall   num_mul2
    movff   v_num_lo,v_num_digit_lo
    movff   v_num_hi,v_num_digit_hi
    rcall   num_mul2
    rcall   num_mul2
    rcall   num_add_digit
    ;
    ; add new digit
    ;
    movff   v_tmp,v_num_digit_lo
    clrf    v_num_digit_hi
    rcall   num_add_digit

    bsf     b_num_started
    bra     parse_dec_loop


num_mul2:
    bcf     STATUS,C
    rlcf    v_num_lo,f
    rlcf    v_num_hi,f
num_checkc:
    btfsc   STATUS,C
    bsf     b_num_overflow
    return

num_add_digit:
    movf    v_num_digit_lo,w
    addwf   v_num_lo,f
    movf    v_num_digit_hi,w
    addwfc  v_num_hi,f
    bra     num_checkc

parse_bad_digit:
    bsf     b_num_bad_digit

    ;
    ; end of parse
    ;  b_num_overflow  is set if overflowed
    ;  b_num_bad_digit is set if lat digit was bad
    ;  b_num_started   is set if any good digits were parsed
    ;
parse_end:
    return