Abstract: A system and method for speculative forwarding of packets received by a router, wherein each packet includes phits and wherein one or more phits include a cyclic redundancy code (CRC). A packet is received and phits of the packet are forwarded to router logic. A cyclic redundancy code for the packet is calculated and compared to the packet's cyclic redundancy code. An error is generated if the cyclic redundancy codes don't match. If the cyclic redundancy codes don't match, a phit of the packet is modified to reflect the error, the CRC is corrected and the corrected CRC is forwarded to the router logic along with the phit reflecting the CRC error. At the router logic, a check is made to see if the packet is still within the router logic. If the packet is still within the router logic and there was a CRC error, the packet is discarded. If, however, the packet is no longer within the router logic and there was a CRC error, the packet is modified so that the next router discards the packet.

Abstract: A system and method for speculative forwarding of packets received by a router, wherein each packet includes phits and wherein one or more phits include a cyclic redundancy code (CRC). A packet is received and phits of the packet are forwarded to router logic. A cyclic redundancy code for the packet is calculated and compared to the packet's cyclic redundancy code. An error is generated if the cyclic redundancy codes don't match. If the cyclic redundancy codes don't match, a phit of the packet is modified to reflect the error, the CRC is corrected and the corrected CRC is forwarded to the router logic along with the phit reflecting the CRC error. At the router logic, a check is made to see if the packet is still within the router logic. If the packet is still within the router logic and there was a CRC error, the packet is discarded. If, however, the packet is no longer within the router logic and there was a CRC error, the packet is modified so that the next router discards the packet.

Abstract: A memory daughter card (MDC) is described, having a very high-speed serial interface and an on-card MDC test engine that allows one MDC to be directly connected to another MDC for testing purposes. In some embodiments, a control interface allows the test engine to be programmed and controlled by a test controller on a test fixture that allows simultaneous testing of a single MDC or one or more pairs of MDCs, one MDC in a pair (e.g., the “golden” MDC) testing the other MDC of that pair. Other methods are also described, wherein one MDC executes a series of reads and writes and other commands to another MDC to test at least some of the other card's functions, or wherein one port executes a series of test commands to another port on the same MDC to test at least some of the card's functions.

Abstract: A memory controller and method that provide a read-refresh (also called “distributed-refresh”) mode of operation, in which every row of memory is read within the refresh-rate requirements of the memory parts, with data from different columns within the rows being read on subsequent read-refresh cycles until all rows for each and every column address have been read, scrubbing errors if found, thus providing a scrubbing function that is integrated into the read-refresh operation, rather than being an independent operation. For scrubbing, an atomic read-correct-write operation is scheduled. A variable-priority, variable-timing refresh interval is described. An integrated card self-tester and/or card reciprocal-tester is described. A memory bit-swapping-within-address-range circuit, and a method and apparatus for bit swapping on the fly and testing are described.

Abstract: A memory controller and method that provide a read-refresh (also called “distributed-refresh”) mode of operation, in which every row of memory is read within the refresh-rate requirements of the memory parts, with data from different columns within the rows being read on subsequent read-refresh cycles until all rows for each and every column address have been read, scrubbing errors if found, thus providing a scrubbing function that is integrated into the read-refresh operation, rather than being an independent operation. For scrubbing, an atomic read-correct-write operation is scheduled. A variable-priority, variable-timing refresh interval is described. An integrated card self-tester and/or card reciprocal-tester is described. A memory bit-swapping-within-address-range circuit, and a method and apparatus for bit swapping on the fly and testing are described.