AK8996 Datasheet, PDF (50/74 Pages) Asahi Kasei Microsystems – Pressure Sensor Interface IC

[AK8996/W]
Serial Interface Description
The AK8996 writes data to and reads data from the EEPROM and control register (volatile memory) through a
three-wire synchronous serial interface, consisting of SCLK, SDI/O and CS. The serial interface circuit in its
input standby state detects the CS high signal and captures data from SDI/O in sync with the rising edge of the
SCLK, and outputs data from SDI/O synchronous with the rising edge of SCLK. Input data contains three
instruction bits (12 - 10), five address bits (A4 - A0) and eight data bits (D7 - D0). Provide the data in the order
of I2 → I0 → A4 → A0 → D7 → D0.
On the WRITE instruction, allow 5msec or more write time for EEPROM and 300nsec or more write time for
the control register (see Twr in 6) Digital AC Characteristics in the Electrical Characteristics section). For the
READ instruction, data is written up to 8CLK for SCLK (any values are acceptable because the data is
ignored) and the data output starting at the rising edge of 9CLK is read out.
1) Data Configuration
Configuration of data written to or read out through the serial interface is shown below. There are 16 specific
bits of data in total comprised of three instruction bits, five address bits and eight data bits.
Instruction
Address
Data
I2 I1 I0 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Data input direction
2) Description of Instructions
Instruction codes are summarized below.
Code ^Note)
I2
I1
I0
Instruction
Description
1
1
0 EEPROM read Reads out the data written in the EEPROM
(Read Mode)
1
0
1 EEPROM write Writes data to the EEPROM. Write time (from 16^th SCLK
(Write Mode) rising edge to CS falling edge) requires 5msec or more.
EEPROM batch If the 19h address is written, input data is written to all
write
addresses. Write time (from 16^th SCLK rising edge to CS
(Write Mode) falling edge) requires 10msec or more.
0
1
0 Control reg. read Reads out the data written in the control register.
(Read Mode)
0
0
1 Control reg. write Writes the data to the control register. Write time (from
(Write Mode) 16^th SCLK rising edge to CS falling edge) requires
300nsec or more.
Note) Instructions other than this are prohibited.
MS1055-E-02
50
2011/12