DEPTH/WIDTH ADJUSTABLE FIFO BUFFER FOR VARIABLE WIDTH DATA TRANSFER

摘要

PROBLEM TO BE SOLVED: To obtain the depth/width adjustable FIFO buffer which is applicable for the transfer of variable width data. ;SOLUTION: A FIFO buffer (65) has read/write registers (73 and 75) consisting of two parts, which are controlled independently to transfer 16-bit or 32-bit words without wasting the register space in the FIFO buffer (65) even when the 16-bit words are transferred. When the 16-bit words are transferred by narrowing down the FIFO buffer (65), the storage space is made deep. Consequently, the FIFO buffer register (72) can be used at a maximum whichever of the 16-bit parallel data and 32-bit parallel data are interfaced. The FIFO buffer (65) is a buffer which serves as a slave only for a host processor and can not start data output to the FIFO buffer (65), but the structure can be held simple and small-sized.;COPYRIGHT: (C)1996,JPO