HT23C256

HT23C256 CMOS 32K×8-Bit Mask ROM Features Operating voltage 2.7V~5.5V Low power consumption – Operation: 25mA max. (V CC=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 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 microprocessors, 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. Block Diagram 1 24th Aug ’98 HT23C256 Pin Assignment Pin Description Pin Name A0~A14 D0~D7 CE/CE/OE1/OE1 OE/OE/NC VSS VCC NC I/O I O I I I I — Address inputs Data outputs Description Chip enable/Output enable input Output enable input Negative power supply Positive power supply No connection Operation Truth Table Mo...