tone_isr.ss

AMIS單晶片開發範本

// ----------------------------------------------------------------------------
// Copyright (c) 2008 Semiconductor Components Industries, LLC
// (d/b/a ON Semiconductor). All Rights Reserved.
//
// This code is the property of ON Semiconductor and may not be redistributed
// in any form without prior written permission from ON Semiconductor. The
// terms of use and warranty for this code are covered by contractual
// agreements between ON Semiconductor and the licensee.
// ----------------------------------------------------------------------------
// Tone_ISR.ss
// - Contains Tone_TIMER_ISR routine
// - A 2 kHz tone is toggled on and off every time the timer expires.
//   The 2 kHz tone is mixed with the pass-through audio.
// ----------------------------------------------------------------------------
// $Revision: 1.16 $
// $Date: 2008/10/29 18:00:25 $
// ----------------------------------------------------------------------------
#include <boss.inc>
#include <bat.inc>
#include "Tone.inc"  
#include "Tone_internal.inc"  

    Mem_Start_Reloc_Segment(Tone_segment, SYSTEM_MEMORY_TYPE_P, 0x1000)

// -----------------------------------------------------------------------------
// Function:      Tone_TIMER_ISR
// Description:   This interrupt occurs at the end of each timer time-out period
//                according to the timer configuration in the application. When
//                this interrupt happens, the YL_TONE_STATUS flag is toggled. 
//                The state of YL_TONE_STATUS flag is checked in the 
//                Tone_Generation  function. A tone will be generated if 
//                YL_TONE_STATUS is set to TONE_ON.
// Clock cycles:  Min: 16   Max: 18
// Modifies:      None
// -----------------------------------------------------------------------------
// Control Registers
// -----------------------------------------------------------------------------
.global Tone_TIMER_ISR                                        
Tone_TIMER_ISR:

    PUSH ST
    CLR ST
    PUSH AE
    PUSH AH                       
    
    // Check Tone On/off flag (i.e. YL_TONE_STATUS)
    // If YL_TONE_STATUS is on, turn YL_TONE_STATUS off.
    // If YL_TONE_STATUS is off, turn YL_TONE_STATUS on.
    
    LD A, YL_TONE_STATUS, Y
    CMSI A, TONE_ON
    BRA turn_tone_off, Z
    
    // Tone is off.  Therefore, turn on the tone by setting
    // the YL_TONE_STATUS flag to TONE_ON
    LDSI A, TONE_ON
    BRA tone_timer_isr_end
    
turn_tone_off:
    // Tone is on. Therefore, turn off the tone by setting
    // the YL_TONE_STATUS flag to TONE_OFF
    LDSI A, TONE_OFF

tone_timer_isr_end:
    LD YL_TONE_STATUS, A, Y
    POP AH
    POP AE
    POP ST  
    Enable_Int
    RET R3