Hardware Stack Underflow error

	title "Program"
	include "p16f84a.inc"
	__CONFIG   _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC

	ORG 0X000
;===== variables ===========
count1 equ 0xC
value equ 0xD

;===== end variables =======

;===== set ports ======
	bsf STATUS,RP0 ;set PORTB, 0 to input, others to output
	movlw 0x1C	   
	movwf TRISA
	movlw 0xFF
	movwf TRISB
	bcf STATUS, RP0
; ====== end ======

	movlw 0x2
	movwf PORTA

start ;========================== digit 1 ======================
	movwf value
	btfsc PORTB, 0
	goto start
	btfsc PORTB,1
	goto start
	btfsc PORTB, 2
	goto start
	btfsc PORTB, 3
	goto start
	btfsc PORTB, 4
	goto start
	btfsc PORTB, 5
	goto start
	btfsc PORTB, 6
	goto start
	btfsc PORTB, 7
	goto start
	btfsc PORTA, 4
	goto start

	btfss PORTA, 3
	goto start
loop decfsz count1,1
	goto loop
	btfss PORTA,3

	goto start
	btfsc PORTA, 2
	goto term ; calling this sub causes error!  Everything else is ok!
	goto start

term
	movlw 0x0
	movwf value
return

	end

term
	movlw	0x0
	movwf	value
hang	goto	hang