4 operation, 1 i2c bus data format, The i – Renesas H8S/2111B User Manual
Page 341: C bus interface has an i, C bus format and a serial format. 13.4.1 i, C bus data format the i, Figure 13.3 i, C bus data format (i, C bus format), Figure 13.4 i
Rev. 1.00, 05/04, page 307 of 544
13.4 Operation
The I
2
C bus interface has an I
2
C bus format and a serial format.
13.4.1 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 13.3.
The first frame following a start condition always consists of 9 bits.
The serial format is a non-addressing format with no acknowledge bit. This is shown in
figure 13.4.
Figure 13.5 shows the I
2
C bus timing.
The symbols used in figures 13.3 to 13.5 are explained in table 13.6.
S
A
SLA
7
n
R/
W
DATA
A
1
1
m
1
1
1
A/
A
1
P
1
Transfer bit count
(n = 1 to 8)
Transfer frame count
(m
≥ 1)
S
SLA
7
n1
7
R/
W
A
DATA
1
1
1
m1
1
A/
A
1
S
1
SLA
R/
W
1
1
m2
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
≥ 1)
Figure 13.3 I
2
C Bus Data Format (I
2
C Bus Format)
S
DATA
8
n
DATA
1
1
m
P
1
FS = 1 and FSX = 1
Transfer bit count
(n = 1 to 8)
Transfer frame count
(m
≥ 1)
Figure 13.4 I
2
C Bus Data Format (Serial Format)