描述 Description

The AK6440B is a 4096bit, serial, read/write, non­volatile memory device fabricated using an advanced CMOS EEPROM technology. The AK6440B has 4096bits of memory organized into 256 registers of 16 bits each. The AK6440B can operate full function under wide operating voltage range from 1.8V to 5.5V. The charge up circuit is integrated for high voltage generation that is used for write operation. The AK6440B can connect to the serial communication port of popular one chip microcomputer directly (3 line negative clock synchronous interface). At write operation, AK6440B takes in the write data from data input pin (DI) to a register synchronously with rising edge of input pulse of serial clock pin (SKB). And at read operation, AK6440B takes out the read data from a register to data output pin (DO) synchronously with falling edge of SKB. The AK6440B has 4 instructions such as READ, WRITE, WREN (write enable) and WRDS (write disable). Each instruction is organized by op­code block (8bits), address block (8bits) and data (8bits×2). When input level of SKB pin is high level and input level of chip select (CSB) pin is changed from high level to low level, AK6440B can receive the instructions. Special features of the AK6440B include : automatic write time­-out with auto-­ERASE, Ready/BusyB status signal output and ultra-­low standbypower mode when deselected (CSB=high).