The OKI MSM514221B is a high performance 1-Mbit, 256K 4-bit, Field Memory. It is designed for high-speed serial access applications such as HDTVs, conventional NTSC TVs, VTRs, digital movies and Multi-media systems. It is a FRAM for wide or low end use as general commodity TVs and VTRs, exclusively. The MSM514221B is not designed for the other use or high end use in medical systems, professional graphics systems which require long term picture, and data storage systems and others. The 1-Mbit capacity fits one field of a conventional NTSC TV screen. Each of the 4-bit planes has separate serial write and read ports. These employ independent control clocks to support asynchronous read and write operations. Different clock rates are also supported that allow alternate data rates between write and read data streams. The MSM514221B provides high speed FIFO, First-In First-Out, operation without external refreshing: it refreshes its DRAM storage cells automatically, so that it appears fully static to the users.