S1X70000 Datasheet, PDF (164/379 Pages) Epson Company – STANDARD CELL / EMBEDDED ARRAY

Chapter 5 Memory Blocks
5.3 High-Density-Type Dual-Port RAM
5.3.1 Features
• This type of RAM is exclusively designed as dual-port RAM in order to reduce the area
that it occupies.
• Can be configured in a wide range of memory capacities (1k to 64k bits), and provides
superior flexibility for selection of the height-to-width ratio of the layout shape.
Furthermore, if large-capacity memory is required, multiple pieces of memory macros
may be used.
• Can be accessed at High speed and consumes less current than other RAMs of the
same class.
• The chip-select, write-enable, byte write-enable, address, and data-input/output parts
contain a latch circuit, making the RAM capable of clock-synchronized, high-speed
operation.
• The data-input port and data-output port are separated.
• A byte write function is included, allowing the bits of write data to be selected in byte
units.
• The data-output part contains a latch circuit, so that readout data is output
continuously until the next read cycle.
• Libraries are available that use Standard-1-type transistors.
5.3.2 RAM Sizes
The sizes of high-density-type dual-port RAMs vary in a complicated manner depending
on the word/bit configurations. For detailed information on RAM sizes, please contact
the sales division of Epson.
5.3.3 Input Signals and Block Diagrams
Ports 1 and 2 are each capable of performing read and write operations. Each port comes
equipped with a clock input pin, allowing them to be operated with different frequencies
or timing independently of each other.
Be aware that no memory cells can be accessed from two ports at the same time. If
arbitration facilities, busy signals, or the like are required to resolve conflicts, configure a
necessary circuit in the gate-array section external to the macro. (If accessed at the same
time, the read or write operation in that cycle and the data in the accessed memory cell
become indeterminate.)
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EPSON
STANDARD CELL S1K70000 SERIES
EMBEDDED ARRAY S1X70000 SERIES