Datasheet

Section 18 I
2
C Bus Interface [Option]
(This function is not available in the H8S/2695)
Page 866 of 1434 R01UH0166EJ0600 Rev. 6.00
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
18.3 Operation
18.3.1 I
2
C Bus Data Format
The I
2
C bus interface has serial and I
2
C bus formats.
The I
2
C bus formats are addressing formats with an acknowledge bit. These are shown in figures
18.3 (a) and (b). The first frame following a start condition always consists of 8 bits.
The serial format is a non-addressing format with no acknowledge bit. Although start and stop
conditions must be issued, this format can be used as a synchronous serial format. This is shown in
figure 18.4.
Figure 18.5 shows the I
2
C bus timing.
The symbols used in figures 18.3 to 18.5 are explained in table 18.4.
S SLA R/W A DATA A A/A P
1111
n7
1 m
(a) I
2
C bus format (FS = 0 or FSX = 0)
(b) I
2
C bus format (start condition retransmission, FS = 0 or FSX = 0)
n: transfer bit count
(n = 1 to 8)
m: transfer frame count
(m ≥ 1)
S SLA R/W A DATA
111
n17
1 m1
S SLA R/W A DATA A/A P
111
n27
1 m2
111
A/A
n1 and n2: transfer bit count (n1 and n2 = 1 to 8)
m1 and m2: transfer frame count (m1 and m2 ≥ 1)
11
Figure 18.3 I
2
C Bus Data Formats (I
2
C Bus Formats)