| 摘要 |
A pseudo-random built in self test pattern generator is constructed of eight sequential D-flip flops and configured to output 10-bit wide pattern data which conforms to the 8B/1OB transmission protocol. The first and fifth D-flip flops of the array have their outputs split, with one leg of the split directly defining a character bit and the other leg of the split defining an inverted character bit. The outputs of the first, second, seventh and eighth D-flip flops are directed to a four input EXOR gate whose output is connected to the D input of the first D-flip flop of the array. Configured as a recirculating feed back loop, the pattern generator defines a sequence of 10-bit patterns in which no more than five sequential 1s or five sequential 0s are generated either within a pattern or on pattern boundaries. The pattern generator provides 255 Fiber Channel-type transmission characters to a Fiber Channel-type transceiver circuit which serializes the characters into a 1.06 GHz serial datastream and then deserializes the datastream into 10-bit transmission characters. The received transmission characters are analyzed and if they match with patterns transmitted, the transceiver circuit is deemed to be correctly operating at a 1.06 GHz characteristic frequency.
|
