US 5,495,451 AGranted

Apparatus for detecting data input/output states of a plurality of first-in first-out memories

AssigneeGoldstar Electron Co., Ltd.

InventorSung K. Cho

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Abstract

An apparatus for detecting data input/output states of a plurality of FIFO memories, comprising a control signal generator for logically combining a load clock signal, a read clock signal, a write clock signal and a reset signal to generate a clock signal and a mode signal, a clock counting circuit for performing a counting operation for the read clock signal and the write clock signal in response to the clock signal and the mode signal from the control signal generator to generate a count signal, a fullness level value storage unit for storing a plurality of fullness level values, a multiplexer for selecting one of the fullness level values from the fullness level value storage unit in response to a select signal, a signal comparator for comparing an output signal from the multiplexer with the count signal from the clock counting circuit to discriminate whether it is the same as the count signal, a demultiplexer for generating a plurality of status signals in response to an output signal from the signal comparator and the select signal, the status signals being indicative of a fullness level value regarding the number of data currently stored in the corresponding FIFO memory, and a flag generator for generating a plurality of flag signals in response to the status signals from the demultiplexer.

Claims12

Dependent claims

An apparatus for detecting data input/output states of a plurality of first-in first-out memories, comprising:

control signal generation means for logically combining a load clock signal, a read clock signal, a write clock signal and a reset signal to generate a clock signal and a mode signal;
clock counting means for performing a counting operation for the read clock signal and the write clock signal in response to the clock signal and the mode signal from said control signal generation means to generate a count signal indicative of the number of data currently stored in a corresponding one of the first-in first-out memories;
fullness level value storage means for storing a plurality of fullness level values, each of the fullness level values being indicative of the number of data storable at the maximum in a corresponding one of a plurality of levels of the corresponding first-in first-out memory;
multiplexing means for selecting one of the fullness level values from said fullness level value storage means in response to a select signal;
signal comparison means for comparing an output signal from said multiplexing means with the count signal from said clock counting means to discriminate whether it is the same as the count signal;
demultiplexing means for generating a plurality of status signals in response to an output signal from said signal comparison means and the select signal, the status signals being indicative of a fullness level value regarding the number of data currently stored in the corresponding first-in first-out memory;
and
flag generation means for generating a plurality of flag signals in response to the status signals from said demultiplexing means.

5 more elements

Dependencies are inferred from the claim text.