CRC (Cyclic Redundancy Check) data checking method and checking circuit applied to Expander

Abstract

The invention provides a CRC (Cyclic Redundancy Check) data checking method and checking circuit applied to Expander, and the method comprises the following steps: receiving input data from external equipment, and directly writing the input data into a receiving FIFO (First In First Out) of the Expander; reading the written input data from the receiving FIFO, and judging the frame type of the input data; sending the input data to a descrambler only when the read input data is an address frame; filtering primitive information from the input data; and descrambling the filtered input data, positioning CRC data in the input data by using a counter, and performing CRC verification on the descrambled data according to the CRC data. According to the scheme of the invention, the Expander link establishment time is shortened, the circuit area is reduced, and the link establishment efficiency of the Expander system is improved.

Description

technical field [0001] The invention belongs to the technical field of disk verification, and in particular relates to a CRC data verification method and a verification circuit applied to an Expander. Background technique [0002] SAS (Serial Attached SCSI) uses a serial interface to obtain a higher transmission speed, and realizes the interconnection and data transmission between the SAS controller and the SATA device through the STP protocol (SATA Channel Protocol). The SAS controller supports the management of large-scale disks through one-level or multi-level Expander (disk expander), providing high-performance, high-flexibility storage expansion solutions. [0003] For the Expander, the received data will be stored in the receiving queue (FIFO) first, and then the data in the FIFO will be read out for descrambling (Descramble) and CRC check, thereby establishing the data between the external device and the Expander Link. The whole process is as figure 1 and 2 shown....

AI Technical Summary

Problems solved by technology

[0005] It can be seen that the Expander in the prior art not only performs CRC checks on all types of frames including data frames and address frames, but also performs CRC checks when searching and storing CRC data. Consumes multiple clock cycles, which significantly prolongs the chain establishment time

If the CRC sorting circuit is set outside the FIFO, the circuit area will be increased at the same time, thus affecting the performance of the entire system

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