AK9844A Datasheet, PDF (3/17 Pages) Asahi Kasei Microsystems – 4Kbit EEPROM with 4ch 8bit D/A Converter

ASAHI KASEI
[AK9844A]
Functional Description
The AK9844A 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 AK9844A can connect to the serial communication port of popular one chip microcontrollers
directly (3 line negative clock synchronous interface). At write operation, the AK9844A takes in the
write data from the DI pin to a register synchronously with rising edge of the SK pin. At read
operation, the AK9844A takes out the read data from a register to the DO pin synchronously with
falling edge of the SK pin.
The AK9844A 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(8bits x 2).
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.
000000000
011111111
100000000
100000011
Memory Block
DAC Register Block
$000
$0FF
$100
$103
100000000
100000001
100000010
100000011
Digital input data
for DAC (A00)
Digital input data
for DAC (A01)
Digital input data
for DAC (A02)
Digital input data
for DAC (A03)
$100
$101
$102
$103
Figure 1. Configuration of the EEPROM section
DAD05E-00
-3-
2005/03