; TITLE		count up and down, 1 to 4 to 1.
;

; count from 0-6 then repeat.

DEFMOD count( rc, ic[0:2], oc[0:2] )
	CHIP Inel_arch

	PIN ic[0:2]
	PIN oc[0:2]
	PIN rc

	T_TAB ( rc ic2 ic1 ic0 >> oc2 oc1 oc0 )
		1  x  x  x  :  0  1  1; reset to 2 (which displays 3)
		0  0  0  0  :  0  0  1
		0  0  0  1  :  0  1  0
		0  0  1  0  :  0  1  1
		0  0  1  1  :  1  0  0
		0  1  0  0  :  1  0  1
		0  1  0  1  :  1  1  0
		0  1  1  0  :  0  0  0 



ENDMOD

; Offset/up down Module 							
;	Convert 0-6 to 1-4-1			
;	Sequence: 1,2,3,4,3,2,1,...				

; 
DEFMOD translate( rt, it[0:2], ot[0:2] )
	CHIP Intel_arch	
	
	PIN it[0:2]	; current value of the sequence
	PIN ot[0:2]	; next value of the sequence
	PIN rt

	T_TAB (rt it2 it1 it0 >> ot2 ot1 ot0)
		1  x  x  x  :  0  1  1
		0  0  0  0  :  0  0  1
		0  0  0  1  :  0  1  0
		0  0  1  0  :  0  1  1 
		0  0  1  1  :  1  0  0
		0  1  0  0  :  0  1  1
		0  1  0  1  :  0  1  0
		0  1  1  0  :  0  0  1


ENDMOD

CHIP    FUN_SEQ  NFX780_84		

; INPUTS 

PIN 	47		clock				; Clock input on pin 77
PIN	48		reset				; Counter Reset Flag 

; OUTPUTS 
                       			;  +---s6---+
PIN     34      s0  	  	   	;  |        |
PIN     35      s1     			; s5        s4
PIN     36      s2      		;  |        |
PIN     37      s3      		;  +---s3---+
PIN     39      s4      		;  |        |
PIN     40      s5      		; s2        s1
PIN     41      s6      		;  |        |
                        		;  +---s0---+

PIN	sequence[0:2]	; the output of translate
;PIN	next[0:2]	; a local register?
PIN	count[0:2]	; input to counter
PIN	next_count[0:2]	; output from counter, input to translate

; UNUSED PINS 

PIN	[49:51]	unused[0:2]
PIN	[77:78] unused[3:4]


; Move to the next value of the sequence on the negative edge of the clock 

MODULE count( rc=reset, ic[0:2]=count[0:2], oc[0:2]=next_count[0:2] )
MODULE translate( rt=reset, it[0:2]=next_count[0:2], ot[0:2]=sequence[0:2] )

EQUATIONS

	count[0:2] := next_count[0:2] ;new input to counter = last output from counter
	count[0:2].ACLK = /clock

; Display the current sequence value on the 7-seg display	

T_TAB ( sequence2 sequence1 sequence0 >> s0 s1 s2 s3 s4 s5 s6 )
        0  0  0  :  1  1  1  0  1  1  1  ;  0  
        0  0  1  :  0  1  0  0  1  0  0  ;  1
        0  1  0  :  1  0  1  1  1  0  1  ;  2
        0  1  1  :  1  1  0  1  1  0  1  ;  3
        1  0  0  :  0  1  0  1  1  1  0  ;  4
        1  0  1  :  1  1  0  1  0  1  1  ;  5
        1  1  0  :  1  1  1  1  0  1  1  ;  6
        1  1  1  :  0  1  0  0  1  0  1  ;  7

SIMULATION

	VECTOR in_a := [  reset, count2,  count1,  count0 ]
	VECTOR seg_display := [s0, s1, s2, s3, s4, s5, s6]

	TRACE_ON in_a comp seg_display

        FOR i:=0 TO 15 DO
		BEGIN
		SETF in_a := i
		END