【AMBA AHB总线专题讨论】

zhb129 · 发表于 2014-7-8 20:28:14

回复 488# lulanlanily

1. 在exclusive access中这段话的意思吗？
The minimum number of bytes to be monitored during an exclusive operation is defined by the length and size of the transaction. It is acceptable to monitor a larger number of bytes, up to 128 which is the maximum of an exclusive access. However, this might result in occasions when the exclusive access is actually successful but is indicated as failing because a neighboring byte was updated.最后一句话是怎么理解。//我的理解，独占访问时，检测的最小字节数就是这个brust的长度，如果要要检测独占访问的最大长度，也是可以的。但是这可能导致一个本来成功的独占访问被误作为失败，因为你检测的范围超出了本次独占访问，那么相邻的字节被改写的话，会被视作失败。

2.A slave that supports exclusive access must have monitor hardware. It is recommended that such a slave has a monitor unit for each exclusive-capable master ID that can access it. A single-ported slave can have a standard exclusive access monitor external to the slave, but multiported slaves might require internal monitoring.这里的监视的是master ID ，它和ARID，AWID中的ID有什么区别？到底监视的哪个？
//就是master发出的ID，AWID，ARID都属于masterID。

3.The value of the ARCACHE[3:0] or AWCACHE[3:0] signals must guarantee that the slave that is monitoring the exclusive access sees the transaction. For example, an exclusive access being monitored by a slave must not have an ARCACHE[3:0] or AWCACHE[3:0] value that indicates that the transaction is cacheable.这段话是怎么理解的？
//没搞懂