| 摘要 |
A mechanism is provided that allows partial reading of storage locations, such as statistics counters, by providing a temporary read data storage latch on a peripheral device. The latches are updated with fresh data from an address storage location whenever any one of the following conditions is met: 1. The address accessed by the host differs from the previous access; 2. The host has written to the device prior to the current read; or 3. When accessing the same location sequentially, one or more bytes of the second read have already been read by the host in a previous read. These rules allowed for byte- or word-wise write/read/verify cycles; byte- or word-wise reads of dynamic data; and byte, word, or double-word with polling of registers. With this mechanism, it is impossible for the host to erroneously end up with 01ff (hex) as it reads a four byte register a byte at a time when the register increments from 00ff to 0100 between the sequential reads.
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