[AK09915]
10.1.2.Reading Data
Input the R/W control bit (R/W = “1”) and 7-bit register address on SI pin in synchronous with the first 8-bit of
the 16 bits of a serial clock input on SK pin. Then AK09915 outputs the data held in the specified register with
MSB first from SO pin.
When clocks are input continuously after one byte of data is read, the address is incremented and data in the
next address is output. Accordingly, after the falling edge of the 15th clock and CSB pin is “L”, the data in the
next address is output on SO pin. When CSB pin is driven “L” to “H”, SO pin is placed in the high-impedance
state.
AK09915 has three incrementation lines; 00h to 18h, 30h to 32h and 60h to 62h. In line 00h to 18h, the
incrementation depends on FIFO bit. When FIFO function is disabled, AK09915 increments as follows: 00h
01h 02h 03h 10h 11h ... 18h 00h 01h … . When FIFO function is enabled: 00h 01h
02h 03h 10h 11h ... 18h 11h 12h ... . In line 30h to 32h and 60h to 62h, it increments as:
30h 31h 32h 30h …, and 60h 61h 62h 60h … .
33h to 35h and 37h are reserved addresses. Do not access to those addresses.
When specified address is other than 00h to 18h, 30h to 37h and 60h to 62h, AK09915 recognizes that it is not
selected and keeps SO pin in high-impedance state. Therefore, user can use other addresses for other devices.
CSB
1
2
3
4
5
6
7
8
9
10
11
12
13 14
15
16
SK
SI
(INPUT)
RW A6
A5
A4
A3
A2
A1
A0
Hi-Z
Hi-Z
SO
(OUTPUT)
D7
D6
D5
D4
D3
D2
D1
D0
Figure 10.2 4-wire SPI Reading Data
10.2. I2C Bus Interface
The I2C bus interface of AK09915 supports the Standard mode (100 kHz max.), the Fast mode (400 kHz max.),
and High-speed mode (Hs-mode, 2.5 MHz max.).
10.2.1.Data Transfer
To access AK09915 on the bus, generate a start condition first.
Next, transmit a one-byte slave address including a device address. At this time, AK09915 compares the slave
address with its own address. If these addresses match, AK09915 generates an acknowledgement, and then
executes READ or WRITE instruction. At the end of instruction execution, generate a stop condition.
015006484-E-02
2016/7
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AKM [ ASAHI KASEI MICROSYSTEMS ]
