;===========================================================================
; Filename:	RMP_CNTL.asm
;
; Module Name: 	RAMP_CNTL
;
; Initialization Routine: RAMP_CNTL_INIT
;
; Originator:	Digital Control Systems Group
;			Texas Instruments
;
; Description:	This module implements a ramp up and ramp down function. 
;		The output flag variable s_eq_t_flg is set to 7FFFh when the 
;		output variable setpt_value equals the input variable target_value.
;
;			|~~~~~~~~~~~~~~~|
; target_value o------->|		|----->o  setpt_value
;    			|   RAMP_CNTL	|
; 			|		|----->o  s_eq_t_flg
;			|_______________|
;	
; Target:	C2xx core only
;
;=====================================================================================
; History:
;-------------------------------------------------------------------------------------
; 09-15-2000	Release Rev 1.0	
; 10-06-2000    Release Rev 1.1
;===========================================================================
;(To use this Module, copy this section to main system file)
;		.ref	RAMP_CNTL, RAMP_CNTL_INIT	; function call
;		.ref	target_value 			; Inputs
;		.ref	rmp_dly_max, rmp_lo_limit	; Input Parameters
;		.ref	rmp_hi_limit			; Input Parameter
;		.ref	setpt_value, s_eq_t_flg		; Outputs
;===========================================================================
;Module definitions for external reference.
		.def	RAMP_CNTL, RAMP_CNTL_INIT	; function call
		.def	target_value 			; Inputs
		.def	rmp_dly_max, rmp_lo_limit	; Input Parameters
		.def	rmp_hi_limit			; Input Parameter
		.def	setpt_value, s_eq_t_flg		; Outputs
;===========================================================================

target_value	.usect "rmp_cntl",1
setpt_value	.usect "rmp_cntl",1
s_eq_t_flg	.usect "rmp_cntl",1
rmp_delay_cntr	.usect "rmp_cntl",1
rmp_dly_max	.usect "rmp_cntl",1
rmp_lo_limit	.usect "rmp_cntl",1
rmp_hi_limit	.usect "rmp_cntl",1


RAMP_CNTL_INIT:
		LDP	#setpt_value
		SPLK	#0h,setpt_value
		SPLK	#0h,rmp_delay_cntr
		SPLK	#7,rmp_dly_max
		SPLK	#0300h,rmp_lo_limit
		SPLK	#07500h,rmp_hi_limit
		RET

RAMP_CNTL:
		SETC	SXM					; Sign extension mode
		SETC	OVM					; Set Overflow mode
		
		LDP	#target_value
		LACC	target_value
		SUB	setpt_value
		BCND	SET_FLG, EQ		; If Set point = target 
						; set s_eq_t_flg = 7FFFh then exit
		LACC	rmp_delay_cntr
		ADD	#1
		SACL	rmp_delay_cntr
		SUB	rmp_dly_max
		BCND	SRC_EXIT, LT

CHNG_VALUE:
		LACC	target_value
		SUB	setpt_value
		BCND	INC_VALUE, GT

DEC_VALUE	LACC	setpt_value
		SUB	#1
		SACL	setpt_value
		SUB	rmp_lo_limit
		BCND	SRC_1, GEQ
		LACC	rmp_lo_limit
		SACL	setpt_value
		B	SRC_1

INC_VALUE	LACC	setpt_value	   
		ADD	#1
		SACL	setpt_value
		SUB	rmp_hi_limit
		BCND	SRC_1, LEQ
		LACC	rmp_hi_limit
		SACL    setpt_value
SRC_1:
		SPLK	#0, rmp_delay_cntr

SRC_EXIT
		RET

SET_FLG
		SPLK	#7FFFh, s_eq_t_flg
		RET