Datasheet

2003 Apr 10 35
NXP Semiconductors Preliminary specification
Stereo audio codec with SPDIF interface UDA1355H
Table 18 L3-bus write data
Table 19 L3-bus read data
BYTE L3-BUS MODE ACTION
FIRST IN TIME LAST IN TIME
BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7
1address device address 01A010000
2 data transfer register address 0 A6 A5 A4 A3 A2 A1 A0
3 data transfer data byte 1 D15 D14 D13 D12 D11 D10 D9 D8
4data transfer data byte2 D7D6D5D4D3D2D1D0
BYTE L3-BUS MODE ACTION
FIRST IN TIME LAST IN TIME
BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7
1address device address 01A010000
2 data transfer register address 1 A6 A5 A4 A3 A2 A1 A0
3address device address 11A010000
4data transfer register address 0or1A6A5A4A3A2A1A0
5 data transfer data byte 1 D15 D14 D13 D12 D11 D10 D9 D8
6data transfer data byte2 D7D6D5D4D3D2D1D0
11 I
2
C-BUS DESCRIPTION
11.1 Characteristics
The bus is for 2-way, 2-line communication between
different ICs or modules. The two lines are a Serial Data
Line (SDA) and a Serial Clock Line (SCL). Both lines must
be connected to the supply voltage (V
DD
) via a pull-up
resistor when connected to the output stages of a
microcontroller. For a 400 kHz IC the recommendation for
this type of bus from NXP Semiconductors must be
followed (e.g. up to loads of 200 pF on the bus a pull-up
resistor can be used, between 200 to 400 pF a current
source or switched resistor must be used). Data transfer
can only be initiated when the bus is not busy.
11.2 Bit transfer
One data bit is transferred during each clock pulse (see
Fig.17). The data on the SDA line must remain stable
during the HIGH period of the clock pulse as changes in
the data line at this time will be interpreted as control
signals. The maximum clock frequency is 400 kHz. To be
able to run on this high frequency all the inputs and outputs
connected to this bus must be designed for this high speed
I
2
C-bus according the NXP specification.
handbook, full pagewidth
MBC621
data line
stable;
data valid
change
of data
allowed
SDA
SCL
Fig.17 Bit transfer on the I
2
C-bus.