;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST1.ASM
;
; Test basic incrementing and decrementing instructions and
; skipping.
;
; Output an incrementing pattern to PORTB, up to 20 and
; then start decrementing back down to zero, repeat forever.
;
count   equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   clrf	count

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

incloop:
	movf	count, W	; W <= count
	movwf	portb		; PORTB <= W
	incf	count, W	; W <= count + 1
	movwf	count
	xorlw	14h		; Compare W with 20
	btfss	STATUS, ZERO
	goto	incloop

	; OK.  We hit FF, Now decrement for a while
decloop:
	movf	count, W	; W <= count
	movwf	portb		; PORTB <= W
	decf	count		; W <= count - 1
	btfss	STATUS, ZERO
	goto	decloop

	goto	incloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST2.ASM
;
; Test ADD instructions
;
; Output an ever increasing series (x = x + 10) to PORTB.
; Watch the Carry bit pulse HIGH when it wraps.
;
x	equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   clrf	x

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

addloop:
	movlw	D'10'
	addwf	x, W		; W <= W + X
	movwf	x		; X <= W
	movwf	portb		; PORTB <= W
	goto	addloop
;
        org     01FFh
		  goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST3.ASM
;
; Test SUB instructions.  Output to PORTB a series of numbers, x = x - 10.
; Watch the Carry/Borrow bit pulse LOW when it wraps.
;
;
x	equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   movlw	D'20'
	movwf	x

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

subloop:
	movlw	D'10'
	subwf	x, W		; W <= W + X
	movwf	x		; X <= W
	movwf	portb		; PORTB <= W
	goto	subloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST4.ASM
;
; Test the Rotate instructions.  Cause a single '1' to rotate right
; a bunch of times, then rotate left, then repeat again forever.
;
x	equ	14
count	equ	15
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	movlw	D'20'
	movwf	count

	clrf	x
	bsf	STATUS, CARRY
	rrf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	bcf	STATUS, CARRY

	; OK.  Rotate 20 times
rloop1	rrf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	decfsz	count
	goto	rloop1

;*** Now go the other way
	movlw	D'236'
	movwf	count

	clrf	x
	bsf	STATUS, CARRY
	rlf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	bcf	STATUS, CARRY

	; OK.  Rotate 20 times
rloop2	rlf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	incfsz	count
	goto	rloop2

done	goto	main
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST5.ASM
;
; Test various Logical operations..  Output incrementing pattern
; to PORTB through contorted logical operations.
;
x	equ	14
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	clrw			; W <= 00000000
	movwf	portb		; PORTB <= W

	;*** Test the Literal Logicals
	;
	iorlw	B'00000001'	; W <= 00000001
	movwf	portb		

	xorlw	B'00000011'	; W <= 00000010
	movwf	portb		

	iorlw	B'11111111'	; W <= 11111111
	andlw	B'00000011'	; W <= 00000011
	movwf	portb		

	;*** Test the File Register Logicals
	;
	; Output 4 (00000100)
	movlw	B'10101010'	; W <= 10101010
	movwf	x		; X <= W
	movlw	B'10101110'
	xorwf	x		; X <= 00000100
	movf	x, W		; Output..
	movwf	portb		

	; Output 5 (00000101)
	movlw	B'10101010'	; W <= 10101010
	movwf	x		; X <= W
	movlw	B'00000101'
	iorwf	x		; X <= 10101111
	movlw	B'01010101'
	andwf	x		; X <= 00000101
	movf	x, W		; Output..
	movwf	portb		

	; Output 6 (00000110)
	movlw	B'11111001'	
	movwf	x		; X <= 11111001
	comf	x		; X <= 00000110
	movf	x, W		; Output..
	movwf	portb		

done	goto	done
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST6.ASM
;
; Test I/O Ports.
;
; Echo anything read on PORTA to PORTB and echo complement to PORTC.
;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

mainloop:
	movf	porta, W	; W <= PortA
	movwf	portb		; PORTB <= W
	xorlw	H'FF'		; Complement W
	movwf	portc		; PORTB <= W
	goto	mainloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C56 is the target processor

; PIC Core Verification Program
;
; TEST7.ASM
;
; Test Register File Banks and address mapping, and Indirect Addressing.
;
; Location count is located in lower half of banks and should be
; accessable regardless of the bank.  Increment
; this counter after switching to each bank.  Write this count
; to locations in upper part of each bank.  Then go back, read
; each value and echo out portb.  Should see incrementing pattern
; on PORTB.
;

INDF	equ	0
FSR	EQU	4

count   equ	9	; This location should be common to all Banks
x0	equ	01eh	; This is in upper part of Bank0
x1	equ	03eh	; This is in upper part of Bank1
x2	equ	05eh	; This is in upper part of Bank2
x3	equ	07eh	; This is in upper part of Bank3


porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   clrw
	tris	portb
	movwf	count
	incf	count

	; Point to a location in upper part of Bank #0
	movlw	x0	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #1
	movlw	x1	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #2
	movlw	x2	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #3
	movlw	x3	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; OK.  Go back and read each count and output to PORTB
	movlw	x0	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x1	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x2	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x3	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB

done	goto	done

;
        org     01FFh
        goto    start
;
     END

;
        LIST    p=16C57 ; PIC16C56 is the target processor

; PIC Core Verification Program
;
; TEST8.ASM
;
; Test CALL and RET instructions..
;
; The 16C57 only has 2 stack levels!

count   equ     14
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	clrf	count
	call	func1
	movwf	portc
	call	func1
	movwf	portc
	call	func2
	movwf	portc
	call	func2
	movwf	portc
	call	func3
	movwf	portc

done	goto	done

func1	incf	count
	movf	count, W
	movwf	portb
	retlw	h'88'

func2	decf	count
	movf	count, W
	movwf	portb
	retlw	h'77'

func3	call 	func1
	movwf	portc
	retlw	h'66'

;
        org     01FFh
        goto    start
;
     END

;
        LIST    p=16C57 ; PIC16C57 is the target processor

; PIC Core Verification Program
;
; TEST9.ASM
;
; Test the TIMER0 free-running timer
;
; Let's just read timer0 as fast as we can, and output it to PORTB.
; Every 20 times through the loop, increment (mod 8) the prescaler.
; Echo the prescaler out PORTC.  So, we should we that PORTB changes
; less frequently as the prescaler increases.  Eventually, the prescaler
; wraps back to zero, and this repeats infinitely.
;
; Verilog-XL note:  A great way to see this is to display the signals:
;    tmr0, portb and portc.  If you do this, you can see the affect
;    pretty clearly.
; 

count   equ     08
scale   equ	09

porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
timer0  equ     01	; Timer0
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output
	
	clrf	scale
loop1:
	movlw	d'20'	
	movwf	count

	movf	scale, W	; Get prescaler
	option			; Program it
	movwf	portc		; Write current prescaler to PORTC

loop2	movf	timer0, W	; Read Timer0
	movwf	portb		; Echo it out PORTB
	decfsz	count		; Do this some number of times
	goto	loop2
	incf	scale		; Increment our prescaler, but..
	movlw	B'00000111'	; keep it to 3 bits.
	andwf	scale
	goto	loop1
	

;
        org     01FFh
        goto    start
;
     END

;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST1.ASM
;
; Test basic incrementing and decrementing instructions and
; skipping.
;
; Output an incrementing pattern to PORTB, up to 20 and
; then start decrementing back down to zero, repeat forever.
;
count   equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   clrf	count

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

incloop:
	movf	count, W	; W <= count
	movwf	portb		; PORTB <= W
	incf	count, W	; W <= count + 1
	movwf	count
	xorlw	14h		; Compare W with 20
	btfss	STATUS, ZERO
	goto	incloop

	; OK.  We hit FF, Now decrement for a while
decloop:
	movf	count, W	; W <= count
	movwf	portb		; PORTB <= W
	decf	count		; W <= count - 1
	btfss	STATUS, ZERO
	goto	decloop

	goto	incloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST2.ASM
;
; Test ADD instructions
;
; Output an ever increasing series (x = x + 10) to PORTB.
; Watch the Carry bit pulse HIGH when it wraps.
;
x	equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   clrf	x

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

addloop:
	movlw	D'10'
	addwf	x, W		; W <= W + X
	movwf	x		; X <= W
	movwf	portb		; PORTB <= W
	goto	addloop
;
        org     01FFh
		  goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST3.ASM
;
; Test SUB instructions.  Output to PORTB a series of numbers, x = x - 10.
; Watch the Carry/Borrow bit pulse LOW when it wraps.
;
;
x	equ     14      ;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   movlw	D'20'
	movwf	x

	; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

subloop:
	movlw	D'10'
	subwf	x, W		; W <= W + X
	movwf	x		; X <= W
	movwf	portb		; PORTB <= W
	goto	subloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST4.ASM
;
; Test the Rotate instructions.  Cause a single '1' to rotate right
; a bunch of times, then rotate left, then repeat again forever.
;
x	equ	14
count	equ	15
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	movlw	D'20'
	movwf	count

	clrf	x
	bsf	STATUS, CARRY
	rrf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	bcf	STATUS, CARRY

	; OK.  Rotate 20 times
rloop1	rrf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	decfsz	count
	goto	rloop1

;*** Now go the other way
	movlw	D'236'
	movwf	count

	clrf	x
	bsf	STATUS, CARRY
	rlf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	bcf	STATUS, CARRY

	; OK.  Rotate 20 times
rloop2	rlf	x, W
	movwf	x
	movwf	portb		; PORTB <= W
	incfsz	count
	goto	rloop2

done	goto	main
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST5.ASM
;
; Test various Logical operations..  Output incrementing pattern
; to PORTB through contorted logical operations.
;
x	equ	14
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	clrw			; W <= 00000000
	movwf	portb		; PORTB <= W

	;*** Test the Literal Logicals
	;
	iorlw	B'00000001'	; W <= 00000001
	movwf	portb		

	xorlw	B'00000011'	; W <= 00000010
	movwf	portb		

	iorlw	B'11111111'	; W <= 11111111
	andlw	B'00000011'	; W <= 00000011
	movwf	portb		

	;*** Test the File Register Logicals
	;
	; Output 4 (00000100)
	movlw	B'10101010'	; W <= 10101010
	movwf	x		; X <= W
	movlw	B'10101110'
	xorwf	x		; X <= 00000100
	movf	x, W		; Output..
	movwf	portb		

	; Output 5 (00000101)
	movlw	B'10101010'	; W <= 10101010
	movwf	x		; X <= W
	movlw	B'00000101'
	iorwf	x		; X <= 10101111
	movlw	B'01010101'
	andwf	x		; X <= 00000101
	movf	x, W		; Output..
	movwf	portb		

	; Output 6 (00000110)
	movlw	B'11111001'	
	movwf	x		; X <= 11111001
	comf	x		; X <= 00000110
	movf	x, W		; Output..
	movwf	portb		

done	goto	done
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C57 is the target processor
;
; PIC Core Verification Program
;
; TEST6.ASM
;
; Test I/O Ports.
;
; Echo anything read on PORTA to PORTB and echo complement to PORTC.
;
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;


start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

mainloop:
	movf	porta, W	; W <= PortA
	movwf	portb		; PORTB <= W
	xorlw	H'FF'		; Complement W
	movwf	portc		; PORTB <= W
	goto	mainloop
;
        org     01FFh
        goto    start
;
     END


;
        LIST    p=16C57 ; PIC16C56 is the target processor

; PIC Core Verification Program
;
; TEST7.ASM
;
; Test Register File Banks and address mapping, and Indirect Addressing.
;
; Location count is located in lower half of banks and should be
; accessable regardless of the bank.  Increment
; this counter after switching to each bank.  Write this count
; to locations in upper part of each bank.  Then go back, read
; each value and echo out portb.  Should see incrementing pattern
; on PORTB.
;

INDF	equ	0
FSR	EQU	4

count   equ	9	; This location should be common to all Banks
x0	equ	01eh	; This is in upper part of Bank0
x1	equ	03eh	; This is in upper part of Bank1
x2	equ	05eh	; This is in upper part of Bank2
x3	equ	07eh	; This is in upper part of Bank3


porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   clrw
	tris	portb
	movwf	count
	incf	count

	; Point to a location in upper part of Bank #0
	movlw	x0	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #1
	movlw	x1	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #2
	movlw	x2	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; Point to a location in upper part of Bank #3
	movlw	x3	; Get Address
	movwf	FSR	; Set index register
	movf	count,W	; Get the count value
	movwf	INDF	; Write using index
	incf	count	; Increment the counter

	; OK.  Go back and read each count and output to PORTB
	movlw	x0	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x1	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x2	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB
	movlw	x3	; Get Address
	movwf	FSR	; Set index register
	movf	INDF,W	; Retrieve the count value to W
	movwf	portb	; Write to PORTB

done	goto	done

;
        org     01FFh
        goto    start
;
     END

;
        LIST    p=16C57 ; PIC16C56 is the target processor

; PIC Core Verification Program
;
; TEST8.ASM
;
; Test CALL and RET instructions..
;
; The 16C57 only has 2 stack levels!

count   equ     14
porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output

main:
	clrf	count
	call	func1
	movwf	portc
	call	func1
	movwf	portc
	call	func2
	movwf	portc
	call	func2
	movwf	portc
	call	func3
	movwf	portc

done	goto	done

func1	incf	count
	movf	count, W
	movwf	portb
	retlw	h'88'

func2	decf	count
	movf	count, W
	movwf	portb
	retlw	h'77'

func3	call 	func1
	movwf	portc
	retlw	h'66'

;
        org     01FFh
        goto    start
;
     END

;
        LIST    p=16C57 ; PIC16C57 is the target processor

; PIC Core Verification Program
;
; TEST9.ASM
;
; Test the TIMER0 free-running timer
;
; Let's just read timer0 as fast as we can, and output it to PORTB.
; Every 20 times through the loop, increment (mod 8) the prescaler.
; Echo the prescaler out PORTC.  So, we should we that PORTB changes
; less frequently as the prescaler increases.  Eventually, the prescaler
; wraps back to zero, and this repeats infinitely.
;
; Verilog-XL note:  A great way to see this is to display the signals:
;    tmr0, portb and portc.  If you do this, you can see the affect
;    pretty clearly.
; 

count   equ     08
scale   equ	09

porta   equ     05      ; I/O register F5
portb   equ     06      ; I/O register F6
portc   equ     07      ; I/O register F7
timer0  equ     01	; Timer0
STATUS  equ     03      ; STATUS register F3
CARRY   equ     0       ; Carry bit in status register
ZERO    equ     2       ;
W	equ	0 
;
;

start   ; Set up TRIS registers
	movlw	0ffh
	tris	porta	; PORTA is Input
	clrw
	tris	portb	; PORTB is Output
	tris	portc	; PORTC is Output
	
	clrf	scale
loop1:
	movlw	d'20'	
	movwf	count

	movf	scale, W	; Get prescaler
	option			; Program it
	movwf	portc		; Write current prescaler to PORTC

loop2	movf	timer0, W	; Read Timer0
	movwf	portb		; Echo it out PORTB
	decfsz	count		; Do this some number of times
	goto	loop2
	incf	scale		; Increment our prescaler, but..
	movlw	B'00000111'	; keep it to 3 bits.
	andwf	scale
	goto	loop1
	

;
        org     01FFh
        goto    start
;
     END