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在S3C2440手册的时钟一章里有这样一句:
If HDIVN is not 0, the CPU bus mode has to be changed from the fast bus mode to the asynchronous
bus mode using following instructions(S3C2440 does not support synchronous bus mode).
MMU_SetAsyncBusMode
mrc p15,0,r0,c1,c0,0
orr r0,r0,#R1_nF:OR:R1_iA //请问这句的,#R1_nF:OR:R1_iA是什么意思啊
mcr p15,0,r0,c1,c0,0
还有在VIVI的一段代码中,在做时钟初始化时,是这样来写的
mrc p15, 0, r1, c1, c0, 0 @ read ctrl register
orr r1, r1, #0xc0000000 @ Asynchronous
mcr p15, 0, r1, c1, c0, 0 @ write ctrl register
请问这个是怎么一回事啊,为什么是0xc0000000 |
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