Apparatus to control FIFO memory by using Linear Feedback Shift Register generating Pseudo Random Sequence

摘要

PURPOSE: A FIFO(First In First Out) memory controlling device using an LFSR(Linear Feedback Shift Register) for generating a pseudo random sequence is provided to make a structure be simplified and increase an operation speed by designating a reading/writing position of the FIFO memory using the LFSR. CONSTITUTION: An LFSR(30) uses a specific pseudo random sequence for embodying a reading/writing position being used for controlling a FIFO memory the depth thereof is 'd', and has a 'n' bit length('n' is the least natural number which satisfies "n= log2d"). Whenever the LFSR(30) is operated, each bit value is shifted to one's upper bit. Predetermined bit values for generating the pseudo random sequence out of each bit value of the LFSR(30) are applied as an input signal of an exclusive NOR unit(31), and an output of the exclusive NOR unit(31) is applied to the least significant end input of the LFSR(30).