Datasheet

Section 16 I
2
C Bus Interface (IIC) (Optional)
Rev. 3.00 Mar 21, 2006 page 442 of 788
REJ09B0300-0300
16.4 Operation
The I
2
C bus interface has an I
2
C bus format and a serial format.
16.4.1 I
2
C Bus Data Format
The I
2
C bus format is an addressing format with an acknowledge bit. This is shown in figure 16.3.
The first frame following a start condition always consists of 9 bits.
IIC_0 only is capable of formatless operation, as shown in figure 16.4.
The serial format is a non-addressing format with no acknowledge bit. This is shown in figure
16.5.
Figure 16.6 shows the I
2
C bus timing.
The symbols used in figures 16.3 to 16.6 are explained in table 16.6.
SASLA
7n
R/W DATA A
1
1m
111
A/A
1
P
1
Transfer bit count
(n = 1 to 8)
Transfer frame count
(m = from 1)
S SLA
7n1 7
R/W A DATA
11
1m1
1
A/A
1
S
1
SLA R/W
1
1m2
A
1
DATA
n2
A/A
1
P
1
(a) FS = 0 or FSX = 0
(b) Start condition retransmission FS = 0 or FSX = 0
Upper row: Transfer bit count (n1, n2 = 1 to 8)
Lower row: Transfer frame count (m1, m2 = from 1)
Figure 16.3 I
2
C Bus Data Format (I
2
C Bus Format)
FS = 0 or FSX = 0
AADATA
8n
DATA
11
1m
A/A
1
Transfer bit count
(n = 1 to 8)
Transfer frame count
(m = from 1)
Note: This mode is applied to the PC monitor system standard DDC (Display Data Channel).
Figure 16.4 I
2
C Bus Data Format (Formatless) (IIC_0 Only)