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Princeton Technology Corp.
6-Channel Electronic Volume Controller IC Preliminary
PT2258
FUNCTIONAL DESCRIPTION
Bus Interface
Data are transmitted to and from the microprocessor to the PT2258 via the SDA and SCL. The SDA
and SCL make up the BUS Interface. It should be noted that the pull-up resistors must be connected to
the positive supply voltage.
Data Validity
A data on the SDA Line is considered valid and stable only when the SCL Signal is in HIGH State.
The HIGH and LOW States of the SDA Line can only change when the SCL signal is LOW. Please
refer to the figure below.
SDA
SCL
Start and Stop Conditions
A Start Condition is activated when 1) the SCL is set to HIGH and 2) SDA shifts from HIGH to LOW
State. The Stop Condition is activated when 1) SCL is set to HIGH and 2) SDA shifts from LOW to
HIGH State. Please refer to the timing diagram below.
SCL
SDA
PT2258 pre1.0
5
Updated July 2000
PTC [ PRINCETON TECHNOLOGY CORP ]
