cmpprg_1.asm

A very good POCSAG Paging Protocol Decoder.

;;************************************************************************
;;************************************************************************
;;
;; CMPPRG.asm
;;
;; Assembler source for Continuous Time Programmable Comparator
;;
;; Rev B, 2002 MAR 30
;;
;; Copyright (c) 2000 Cypress Microsystems, Inc. All rights reserved.
;;
;;************************************************************************
;;************************************************************************
;;
export  CMPPRG_1_Start
export _CMPPRG_1_Start

export  CMPPRG_1_SetPower
export _CMPPRG_1_SetPower

export  CMPPRG_1_SetRef
export _CMPPRG_1_SetRef

export  CMPPRG_1_Stop
export _CMPPRG_1_Stop

;; -----------------------------------------------------------------
;;                         Register Definitions
;; -----------------------------------------------------------------
;;
;; Uses 1 Continuous Time Block configured as shown. This API depends
;; on knowing the exact personalization of CR0 and CR2 bitfields
;; for time efficiency.
;;
;; * For a Mask/Val pair, this indicates that the value is
;;   determined by the user either through config-time parameteriza-
;;   tion or run-time manipulation.
;;
;; BIT FIELD	         Mask/Val Function
;; -----------------    	----- 	--------------------
;; COMP_CR0.RES_RATIO_T2B	F0/*	User Parameter (by table)
;; COMP_CR0.GAIN_ATTEN		08/0	Gain
;; COMP_CR0.RES_SOURCE		04/0	Res source VDD
;; COMP_CR0.RES_REF		03/*	User Parameter
;;
;; COMP_CR1.A_OUT		80/0	Output bus disabled		
;; COMP_CR1.COMP_EN		40/*	User Parameter (init: ENABLE)
;; COMP_CR1.CT_NEG_INPUT_MUX	38/4	Neg mux to analog f.b. tap
;; COMP_CR1.CT_POS_INPUT_MUX	07/*	User Parameter (Input selection)
;;
;; COMP_CR2.CP_COMP		80/0	Latch transparent on PH1
;; COMP_CR2.CK_COMP		40/0	Latch transparent
;; COMP_CR2.CC_COMP		20/0	Mode Comparator (not OP-amp)
;; COMP_CR2.BYPASS_OBUS		1C/0	Bypass OFF
;; COMP_CR2.PWR_SELECT		03/0	Power OFF at start-up


include "CMPPRG_1.inc"
include "m8c.inc"

POWERMASK: equ 03h
REFMASK:   equ f0h

;; -----------------------------------------------------------------
;; Start/SetPower - Applies power setting to the module's PSoC blocks
;; 
;; INPUTS: A contains the power setting 0=Off, 1=Low, 2=Med, 3=High
;; OUTUTS: None
;; -----------------------------------------------------------------

 CMPPRG_1_Start:
_CMPPRG_1_Start:
 CMPPRG_1_SetPower:
_CMPPRG_1_SetPower:

    and A, POWERMASK                         ; mask A to protect unchanged bits
    mov X, SP                                ; define temp store location

    push A                                   ; put power value in temp store
    mov A, reg[CMPPRG_1_COMP_CR2]    ; read power value
    and A, ~POWERMASK                        ; clear power bits in A
    or  A, [X]                               ; combine power value with balance of reg.
    mov reg[CMPPRG_1_COMP_CR2], A
    pop A
    ret


;;---------------------------------------------------------------------------------
;;	SetRef: Sets comparator threshold at specified ratio between Low Limit and Vcc
;;	INPUTS: Reference Value from .inc file
;;	OUTPUTS: None
;;	Side Effects: Momentary gain glitch while Ref set to 1.0, then to new value
;;
;;	Ref values shown are for example
;;	1.000  0 0 0 0			
;;	0.937  0 0 0 1
;;	....
;;	0.500  0 1 1 1
;;	....
;;	0.062  0 0 0 0
;;--------------------------------------------------------------------------------

 CMPPRG_1_SetRef:
_CMPPRG_1_SetRef:

    and A, REFMASK                           ; mask A to protect unchanged bits
    mov X, SP                                ; define temp store location
;
    push A                                   ; put reference value in temp store
    mov A, reg[CMPPRG_1_COMP_CR0]    ; read reference value and balance of reg
    and A, ~REFMASK                          ; clear reference bits in A
    or  A, [X]                               ; combine reference value with balance of reg
    mov reg[CMPPRG_1_COMP_CR0], A    ; move complete value back to register
    pop A
    ret




;; -----------------------------------------------------------------
;; Stop - Cuts power to the user module.
;;
;; INPUTS:  None
;; OUTPUTS: None
;; -----------------------------------------------------------------

 CMPPRG_1_Stop:
_CMPPRG_1_Stop:

      
    and reg[CMPPRG_1_COMP_CR2], FCh
    ret