The invention provides a data reading / writing method, a device and a
system for an asynchronous first-in first-out memorizer. The
asynchronous FIFO system comprises a first-in first-out memorizer, an address writing subsystem and an address reading subsystem, wherein the address writing subsystem is composed of an address writing domain gray-code coder, an address writing domain address
jumping and locking unit, an address writing domain trans-
clock synchronous register, an address writing domain gray-code decoder and an address writing unit; and the reading address domain subsystem is composed of an address reading domain gray-code coder, an address reading domain address
jumping and locking unit, an address reading domain trans-
clock synchronous register, an address reading domain gray-code decoder and an address reading unit. When the
asynchronous FIFO memorizer address jumps to an initial address from a non-two-power boundary, the gray-code output is locked so as to realize stable
jumping of the address, so that the
asynchronous FIFO can be realized through the gray-code when the depth of the asynchronous FIFO address is not the power of two, thereby saving memory, hardware and
power consumption.