MSM514221B Datasheet, PDF (1/15 Pages) OKI electronic componets – 262,263-Word x 4-Bit Field Memory

E2L0029-17-Y1
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MSM514221B
262,263-Word ¥ 4-Bit Field Memory
This versio_Mn_S: _MJa₅n₁. ₄1₂99₂8_1B
Previous version: Dec. 1996
DESCRIRTION
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.
Moreover, fully static type memory cells and decoders for serial access enable refresh free serial
access operation, so that the serial read and/or write control clock can be halted high or low for
any duration as long as the power is on. Internal conflicts of memory access and refreshing
operations are prevented by special arbitration logic.
The MSM514221B's function is simple, and similar to a digital delay device whose delay-bit-
length is easily set by reset timing. The delay length, number of read delay clocks between write
and read, is determined by externally controlled write and read reset timings.
Additional SRAM serial registers, or line buffers for the initial access of 256 ¥ 4-bit enable high
speed first-bit-access with no clock delay just after the write or read reset timings.
The MSM514221B is similar in operation and functionality to OKI 2-Mbit Field Memory
MSM518221.
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