Storing/reading several data streams into/from an array of memories

摘要

High speed mass storage devices using NAND flash memories (MDY.X) are suitable for recording and playing back a video data stream under real-time conditions, wherein the data are handled page-wise in the flash memories and are written in parallel to multiple memory buses (MBy). However, for operating with multiple independent data streams a significant buffer size is required. According to the invention, data from different data streams are collected in corresponding different buffers (FIFO 1, . . . , FIFO Z) until the amount of collected data in a current buffer corresponds to a current one of the data blocks. Then, the data of the current data block from the current buffer are stored into memories connected to a current one of the memory buses, wherein the following buffered data block of the related data stream is later on stored into memories connected to a following one of the memory buses, the number of the following memory bus being increased with respect to the number of the current memory bus. These steps are repeated, also for the other ones of the data streams using other available ones of the buffers and other ones of the memory buses. In combination with a corresponding buffer control it is possible to allocate and use a minimum number of buffers in a flexible way.

主权项

1. A method for storing at least two data streams into an array of NAND flash memories, the method comprising:
a) collecting data from different ones of the data streams in corresponding different buffers until an amount of collected data for a current one of the data streams in a current buffer equals a PAGESIZE of a current data block, wherein a number, Z, of buffers is different than a number, N, of the data streams, wherein the array is arranged such that the NAND flash memories are accessed via a number of Y memory buses, to each of which, a number of X memories are connected, and wherein only the current data block can be programmed in a memory at a time, whereinZ=(N*Y)+N+1-∑i=1N-1⁢round_up⁢(i*YN),and wherein storage capacity of each of the buffers is at least X*PAGESIZE;
b) storing the data of the current data block from the current buffer into at least one memory connected to a current one of the memory buses, wherein a following buffered data block of a related data stream is later stored into at least one memory connected to a following memory bus of the memory buses, a number of the following memory bus being increased or decreased, respectively, with respect to a number of the current memory bus; c) repeatedly performing a) and b), and for other ones of the data streams using other available ones of the buffers and other ones of the memory buses.