MC3413 Datasheet, PDF (23/47 Pages) List of Unclassifed Manufacturers – Axis Accelerometer

MC3413 3-Axis Accelerometer
Preliminary Datasheet
10 I2C INTERFACE
10.1 PHYSICAL INTERFACE
The I2C slave interface operates at a maximum speed of 400 kHz. The SDA (data) is an open-
drain, bi-directional pin and the SCL (clock) is an input pin.
The device always operates as an I2C slave.
An I2C master initiates all communication and data transfers and generates the SCL clock that
synchronizes the data transfer. The I2C device address depends upon the state of the VPP pin
during power-up as shown in the table below.
An optional I2C watchdog timer reset can be enabled to prevent bus stall conditions. When
enabled, the sensor I2C circuitry will reset itself if the master takes too long to issue clocks to
the sensor during a read cycle (i.e. if there is a gap in SCL clocks of more than about
200mSec). A status bit can be read to observe if this condition has occurred.
7-bit Device ID 8-bit Address – 8-bit Address – VPP level upon
Write
Read
power-up
0x4C
(0b1001100)
0x98
0x99
GND
0x6C
(0b1101100)
0xD8
0xD9
VDD
Table 10. I2C Address Selection
The I2C interface remains active as long as power is applied to the VDD/VDDIO pin. In
STANDBY state the device responds to I2C read and write cycles, but interrupts cannot be
serviced or cleared. All registers can be written in the STANDBY state, but in WAKE only the
MODE Register can be modified.
Internally, the registers which are used to store samples are clocked by the sample clock gated
by I2C activity. Therefore, in order to allow the device to collect and present samples in the
sample registers at least one I2C STOP condition must be present between samples.
Refer to the I2C specification for a detailed discussion of the protocol. Per I2C requirements,
SDA is an open drain, bi-directional pin. SCL and SDA each require an external pull-up
resistor, typically 4.7kΩ.
mCube Proprietary.
APS-048-0029v1.7
© 2014 mCube Inc. All rights reserved.
23 / 47