| 摘要 |
A system for detecting underflow and overflow errors arising within a ring buffer. When the system receives a data word to be transferred through the ring buffer, the system generates a flow indicator value to be stored with the data word in the ring buffer. This flow indicator value contains information that facilitates determining if an underflow has occured while reading from the ring buffer, or if an overflow has occurred while writing to the ring buffer. Next, the system writes the data word along with the flow indicator value into an entry in the ring buffer. At a later time, the system reads the entry from the ring buffer and generates a predicted flow indicator value. The system compares the flow indicator value read from the ring buffer with the predicted flow indicator value. If the flow indicator value differs from the predicted flow indicator value, the system generates an error signal indicating that an underflow or an overflow has occured. In one embodiment of the present invention, the flow indicator value periodically changes, so that a predictably different flow indicator value is written into the entry in the ring buffer upon successive write operations to the entry. This predictably different flow indicator value allows the system to detect an underflow condition or an overflow condition by comparing the flow indicator value with the predicted flow indicator value. If the flow indicator value read from the ring buffer differs from the predicted flow indicator value, an underflow condition or overflow condition has occured.
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