R8C/20 Group, R8C/21 Group 16. Clock Synchronous Serial Interface
Rev.2.00 Aug 27, 2008 Page 334 of 458
REJ09B0250-0200
Figure 16.39 Operating Timing in Slave Receive Mode (I
2
C Bus Interface Mode) (1)
Figure 16.40 Operating Timing in Slave Receive Mode (I
2
C Bus Interface Mode) (2)
SDA
(master output)
SCL
(master output)
1
8967453
b7
b6
b5
b4
b3
b2
b1
b0
b7
12
SDA
(slave output)
ICDRR register
ICDRS register
Data 1
Process
by program
A
(2) Dummy-read of ICDRR register
Data 1
9
RDRF bit in
ICSR register
1
0
A
(2) Read ICDRR register
SCL
(slave output)
Data 2
SDA
(master output)
SCL
(master output)
8967453
b7
b6
b5
b4
b3
b2
b1
b0
12
SDA
(slave output)
ICDRR register
ICDRS register
Data 1
Process
by program
A
(3) Read ICDRR register
Data 1
9
RDRF bit in
ICSR register
1
0
A
(4) Read ICDRR register
SCL
(slave output)
Data 2
(3) Set ACKBT bit to 1