AK9844 Datasheet, PDF (3/17 Pages) Asahi Kasei Microsystems – 4Kbit EEPROM with 4ch 8bit D/A Converter

ASAHI KASEI
[AK9844]
Functional Description
The AK9844 includes the EEPROM section and the D/A converter section which consists of 4 channel, 8bit
D/A converters with output buffer amps. The EEPROM section is divided into memory block and DAC register
block. The capacity of the memory block is 4096bits which are organized into 256 registers of 16bits each.
The DAC digital input data for D/A converters are stored in the DAC register block which is organized into 4
registers of 8bits each. The address for the memory block is "000000000" to "011111111". The address for
the DAC register is "100000000" to "100000011".
The configuration of the EEPROM section is showed on figure.1.
The AK9844 can connect to the serial communication port of popular one chip microcontrollers directly (3 line
negative clock synchronous interface). At write operation, the AK9844 takes in the write data from the DI pin
to a register synchronously with rising edge of the SK pin. At read operation, the AK9844 takes out the read
data from a register to the DO pin synchronously with falling edge of the SK pin.
The AK9844 has 6 instructions such as READ, WRITE, WREN, WRDS, PDEN and PDDS. The each
instruction is organized by op-code block(8bits), address block(8bits), and data(8bitsÕ2).The output of DAC is
set by storing the DAC digital input data in the DAC register block.
The DO pin is high impedance except that the DO pin outputs the read data and the status signal.
Figure.1 Configuration of the EEPROM section
DAD02E-00
-3-
1999/05