Data Sheet
USB Audio Controller
SN11220ACF
VIII. Two-wire serial port definition
To provide extension capability, SN11220ACF contains a two-wire series bus
circuitry as an interface to MCU. The two wire series bus serves as a slave device
with bit rate up to 400Kbps（fast mode）. MCU can write ten bytes to the
SN11220ACF with 8-bit register address 0x38. MCU can also read ten bytes from
SN11220ACF with 8-bit register address 0x39.
This section just provides simple description of the two-wire series bus. It is
compatible with the I2C slave mode. User can get more detail explanation from the
I2C specification.
The input pin “SCL” is used to get the two wire series bus clock from MCU, and the
open-drain output pin “SDA” is used to send or receive serial signal to/from MCU. As
shown below, “SDA” should be stable when “SCL” is high, and can have transition
only when “SCL” is low.
START and STOP conditions shown below are the exception. Every transaction
begins from a START, and ends with a STOP, or another START（repeated START）.
Sonix Confidential
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Do not copy, reproduce, or distribute without permission
2006 Aug 10, V1.01
SONIX [ SONIX TECHNOLOGY COMPANY ]
