Fujitsu Corporation

Shinzi Hiyama

Hiroshi Nakaide

Toshiaki Hayashi

Satoshi Takeda

Fumihiko Saito

Koji Ikuta

Masashi Ohba

A control method and apparatus for the examination of multiport RAM(s) connected between a CPU on a CPU side and a hardware circuit on a hardware circuit side. The method and apparatus are for use in a device comprising a single RAM or more. For instance, the device may have a first RAM and a second RAM having ports on CPU and a hardware circuit side of the RAMs. Each one port on the CPU side is connected to a CPU. The method and apparatus examine the ports on the hardware circuit as well as the CPU side ports. The method may comprise steps of reading data stored in the first RAM from a port on the hardware circuit of the first RAM and writing the data in the second RAM from the port on the hardware circuit side of the second RAM using a RAM examination controller. The data read from the one port of the first RAM on the CPU side of the RAMs is compared with the data from the other port of the second RAM on the CPU side of the RAMs. The operation of ports of the first RAM and the second RAM on the hardware circuit side of the RAMs is examined.

Controlling method and apparatus for examination of multiport RAM(s)

At a CRC transmission side of a cross connect equipment, a CRC operation is applied to received channel data of each channel independently and sequentially in every sub frame having the same number of channels, series of which sub frames set up a main frame. The resultant CRC code of each channel obtained in a preceding sub frame is coupled to the received channel data of the corresponding channel to apply the same CRC operation to the thus received channel data, thereby the accumulated result of each channel is added in the last sub frame. At a CRC reception side, a cyclic CRC operation similar to that achieved at the CRC transmission side is applied to an outgoing channel data provided with the resultant CRC codes for each channel to obtain CRC results. During the cyclic CRC operation, a CRC error that once occurs is held during the main frame.

Channel data CRC systems for use with cross connect equipment

Growing community of inventors

Kawasaki, Japan

Shinzi Hiyama