AMIS-30622 Datasheet, PDF (27/35 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30622 I²C Microstepping Motordriver
Data Sheet
9.2.4 Inter-IC Control (I²C) Bus
The I²C interface enabled in the AMIS-30622 uses pins 1 and
2 as Data I/O and Serial Clock respectively.
9.2.4.1 Physical Layer
Both SDA and SCK lines are connected to positive supply
voltage via a current source or pull-up resistor. When there
is no traffic on the bus both lines are high. Analog glitch
filters are implemented to suppress spikes with a length up
to 50 ns.
9.2.4.2 Communication on 2-wire Serial Bus Interface
Each communication starts with a Start condition and ends
with a Stop condition. Both conditions are unique and
cannot be confused with data. A high to low transition on
the SDA line while SCK is high defines a Start condition. A
low to high transition on the SDA line while SCK is high
defines a Stop condition. (see figure “Start / Stop
conditions” below). The master always generates the SCK
clock. On every rising transition of SCK the data on SDA is
valid. Data on SDA line is only allowed to change as long as
SCK is low.
Start / Stop Conditions
Every byte sent on SDA must be 8-bit, with the most
significant bit (MSB) transferred first. The number of bytes
that can be transmitted to the AMIS-30622 is restricted to 8
Bit Transfer on 2-wire Serial Bus Interface
bytes. Each byte is followed by an acknowledge bit, which is
issued by the receiving node (figure below).
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