GNU ARM汇编--(八)s3c2440的watchdog
作者：
时间：2016-11-26
来源：网络
收藏
msrcpsr_c,#0xd2@进入中断模式ldrsp,=3072@中断模式的栈指针定义msrcpsr_c,#0xd3@进入系统模式ldrsp,=4096@设置系统模式的栈指针@--------------------------------------------ldrr0,=GPBUPldrr1,=0x03f0strr1,[r0]ldrr0,=GPFCONldrr1,=0x2ea@0x2strr1,[r0]ldrr0,=EXTINT0@ldrr1,=0x8f888@0x0@0x8f888@~(7|(7<<4)|(7<<8)|(7<<16))//低电平触发中断ldrr1,=0xafaaa@0x0@0x8f888//下降沿触发中断strr1,[r0]ldrr0,=EINTPENDldrr1,=0xf0@0b10000strr1,[r0]ldrr0,=EINTMASKldrr1,=0x00@0b00000strr1,[r0]ldrr0,=SRCPNDldrr1,=0x3ff@0x1@0b11111strr1,[r0]ldrr0,=SUBSRCPNDldrr1,=0x1<<13strr1,[r0]ldrr0,=INTPNDldrr1,=0x3ff@0x1@0b11111strr1,[r0]ldrr0,=INTSUBMSKldrr1,=0x0<<13strr1,[r0]ldrr0,=INTMSKldrr1,=0xfffff000@0b00000strr1,[r0]MRSr1,cpsrBICr1,r1,#0x80MSRcpsr_c,r1blmainirq:sublr,lr,#4stmfdsp!,{r0-r12,lr}blirq_isrldmfdsp!,{r0-r12,pc}^irq_isr:ldrr2,=GPBDATldrr1,=0x0e0strr1,[r2]ldrr0,=EINTPENDldrr1,=0xf0strr1,[r0]ldrr0,=SRCPNDldrr1,=0x3ff@0b11111strr1,[r0]ldrr0,=SUBSRCPNDldrr1,=0x1<<13strr1,[r0]ldrr0,=INTPNDldrr1,=0x3ff@0b11111strr1,[r0]movpc,lrdelay:ldrr3,=0xffffffdelay1:subr3,r3,#1cmpr3,#0x0bnedelay1movpc,lrclock_setup:ldrr0,=LOCKTIMEldrr1,=0xffffffffstrr1,[r0]ldrr0,=CLKDIVNldrr1,=(DIVN_UPLL<<3)|(HDIVN<<1)|(PDIVN<<0)strr1,[r0]ldrr0,=UPLLCONldrr1,=(U_MDIV<<12)|(U_PDIV<<4)|(U_SDIV<<0)@Fin=12MUPLL=48Mstrr1,[r0]nopnopnopnopnopnopnopldrr0,=MPLLCONldrr1,=(M_MDIV<<12)|(M_PDIV<<4)|(M_SDIV<<0)@Fin=12MFCLK=400Mstrr1,[r0]movpc,lrmain:ldrr0,=WTDATldrr1,=Count_reloadstrr1,[r0]ldrr0,=WTCNTldrr1,=Countstrr1,[r0]ldrr0,=WTCONldrr1,=(Pre_scaler<<8)|(wd_timer<<5)|(clock_select<<3)|(int_gen<<2)|(reset_enable)strr1,[r0]ledloop:ldrr1,=0x1c0strr1,[r2]bldelayldrr1,=0x1a0strr1,[r2]bldelayldrr1,=0x160strr1,[r2]bldelayldrr1,=0x0e0strr1,[r2]bldelaybledloopundefined_instruction:nopsoftware_interrupt:nopprefetch_abort:nopdata_abort:nopnot_used:nopfiq:nop
程序实现的是:一个正常的流水灯,定时器每隔2s触发一次中断,中断处理中点亮第四个LED.本文引用地址：https://www.eepw.com.cn/article/201611/321723.htm 稍微该一下上面的代码:
.equ int_gen, 0 @关中断
.equ reset_enable, 1 @打开重启信号
打开重启信号,则可以看到每隔2s系统就重启一次.
如果在循环中加入:
ldr r0, =WTCNT @喂狗
ldr r1, =Count
str r1, [r0]
那么,这又是一个标准的流水灯了.而且是有watchdog保护的流水灯了.
加入技术交流群
评论