FIFO device and method thereof

Abstract

The invention relates to an asynchronous FIFO device. The asynchronous FIFO device comprises at least one of an asynchronous FIFO storage device, a first counter module which is capable of producing Gray codes and provided with a writing pointer, a second counter module which is capable of producing Gray codes and provided with a reading pointer, a first shifter which is capable of producing a virtual writing pointer by applying a first delay value to the writing pointer, and a second shifter which is capable of producing a virtual reading pointer by applying a second delay value to the reading pointer, and at least one of a first comparator and a second comparator, wherein the first comparator can output an 'occupied' referent according to the comparison between the writing pointer and the virtual reading pointer, and the second comparator can output an 'unoccupied' referent according to the comparison between the reading pointer and the virtual writing pointer. Therefore, the asynchronous FIFO device is improved.

Description

technical field [0001] The present invention relates generally to first-in-first-out (First Input First Output, FIFO) devices, and more particularly, to asynchronous FIFO devices. Background technique [0002] It is known to use asynchronous first-in-first-out memory to transfer data between first and second clock domains in data processing devices such as microchip designs / implementations, such means are typically used between the first clock domain and the second clock domain. In the case where the two clock domains are asynchronous (that is, the clock frequency of the first clock domain is asynchronous to the clock frequency of the second clock domain). [0003] Generally, a write operation is in one clock domain (may be called a write clock domain) and a read operation is in another clock domain (may be called a read clock domain). The number of occupied storage units in the FIFO memory is an important indicator for judging the empty / full state. Since counting the numb...

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Problems solved by technology

Therefore, the practical application of Gray code to binary code converter is limited to short bit width and low operating frequency

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