General Description

The HT23C256 is a read-only memory with high performance CMOS storage device whose 256K of memory is arranged into 32768 words by 8 bits.

For application flexibility, the chip enable and output enable control pins can be selected as active high or active low. This flexibility not only allows easy interface with most microproc essors, but also eliminates bus contention in multiple bus microprocessor systems. An additional feature of the HT23C256 is its ability to enter the standby mode whenever the chip enable (CE/CE) is inactive, thus reducing current

consumption to below 30µA. The combination of these functions makes the chip suitable for high

density low power memory applications.

Features

• Operating voltage 2.7V~5.5V

• Low power consumption

– Operation: 25mA max. (VCC=5V)

10mA max. (VCC=3V)

– Standby: 30µA max. (VCC=5V)

10µA max. (VCC=3V)

• Access time:150ns max. (VCC=5V)

250ns max. (VCC=3V)

• 32768×8 bits of mask ROM

• Mask options: chip enable CE/CE/OE1/OE1 and output enable OE/OE/NC

• TTL compatible inputs and outputs

• Tristate outputs

• Fully static operation

• Package type: 28-pin DIP/SOP