www.pudn.com > lpc213X_C_application.rar > IRQ.s, change:2004-10-09,size:3349b

;/****************************************Copyright (c)************************************************** 
;**                               Guangzou ZLG-MCU Development Co.,LTD. 
;**                                      graduate school 
;**                                 http://www.zlgmcu.com 
;** 
;**--------------File Info------------------------------------------------------------------------------- 
;** File Name: IRQ.s 
;** Last modified Date:  2004-06-14 
;** Last Version: 1.1 
;** Descriptions: The irq handle that what allow the interrupt nesting.  
;** 
;**------------------------------------------------------------------------------------------------------ 
;** Created By: Chenmingji 
;** Created date:   2004-09-17 
;** Version: 1.0 
;** Descriptions: First version 
;** 
;**------------------------------------------------------------------------------------------------------ 
;** Modified by: 
;** Modified date: 
;** Version: 
;** Descriptions: 
;** 
;********************************************************************************************************/ 
 
 
NoInt       EQU 0x80 
 
USR32Mode   EQU 0x10 
SVC32Mode   EQU 0x13 
SYS32Mode   EQU 0x1f 
IRQ32Mode   EQU 0x12 
FIQ32Mode   EQU 0x11 
 
    CODE32 
 
    AREA    IRQ,CODE,READONLY 
 
    MACRO 
$IRQ_Label HANDLER $IRQ_Exception_Function 
 
        EXPORT  $IRQ_Label                      ; The label for exports 输出的标号 
        IMPORT  $IRQ_Exception_Function         ; The imported labels 引用的外部标号 
 
$IRQ_Label 
        SUB     LR, LR, #4                      ; Calculate the returning address 计算返回地址 
        STMFD   SP!, {R0-R3, R12, LR}           ; Protects the task environments 保存任务环境 
        MRS     R3, SPSR                        ; Protects the status variable 保存状态 
        STMFD   SP, {R3,LR}^                    ; Protects SPSR and SP in user status, Notice: DO NOT write back.保存SPSR和用户状态的SP,注意不能回写 
                                                ; If the SP is written back, it should be adjusted to its appropriate value later.如果回写的是用户的SP，所以后面要调整SP 
        NOP 
        SUB     SP, SP, #4*2 
 
        MSR     CPSR_c, #(NoInt | SYS32Mode)    ; Switch to the System Mode 切换到系统模式  
        
        BL      $IRQ_Exception_Function         ; call the C interrupt handler funtion 调用c语言的中断处理程序 
 
        MSR     CPSR_c, #(NoInt | IRQ32Mode)    ; Switch bak to IRQ mode 切换回irq模式 
        LDMFD   SP, {R3,LR}^                    ; Recover SPSR and SP in user status, Notic: DO NOT write back. 恢复SPSR和用户状态的SP,注意不能回写 
                                                ; If the SP is written back, it should be adjusted to its appropriate value later.如果回写的是用户的SP，所以后面要调整SP 
        MSR     SPSR_cxsf, R3 
        ADD     SP, SP, #4*2                    ;  
 
        LDMFD   SP!, {R0-R3, R12, PC}^          ; 
    MEND 
 
;/* 以下添加中断句柄，用户根据实际情况改变 */ 
;/* Add interrupt handler here，user could change it as needed */ 
 
;Timer0_Handler  HANDLER Timer0 
 
    END 
;/********************************************************************************************************* 
;**                            End Of File 
;********************************************************************************************************/