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IRQ.s
资源名称：SD卡读写模块.rar [点击查看]
上传用户：pudewen666
上传日期：2007-06-08
资源大小：75k
文件大小：3k
源码类别：
微处理器开发
开发平台：
Windows_Unix
- ;/****************************************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
- ;********************************************************************************************************/
