7220 Datasheet, PDF (255/303 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPENDIX
6.7 Control registers
I²C Clock Control Register
b7 b6 b5 b4 b3 b2 b1 b0
I²C clock control register (S2 : address 00DB 16)
B
Name
Functions
After reset R W
0 SCL frequency control bits _{Setup value of Standard clock High speed}
to (CCR0 to CCR4)
CCR4–CCR0 mode
clock mode
4
0 RW
00 to 02 Setup disabled Setup disabled
03
Setup disabled 333
04
Setup disabled 250
05
100 400 (See note)
06
83.3
166
500/CCR value 1000/CCR value
1D
17.2
34.5
1E
16.6
33.3
1F
16.1
32.3
5 SCL mode
specification bit
(FAST MODE)
(at φ = 4 MHz, unit : kHz)
0 : Standard clock mode
1 : High-speed clock mode
0 RW
6 ACK bit
(ACK BIT)
7 ACK clock bit
(ACK)
0 : ACK is returned.
1 : ACK is not returned.
0 : No ACK clock
1 : ACK clock
0 RW
0 _RW
Note: At 4000kHz in the high-speed clock mode, the duty is as below .
“0” period : “1” period = 3 : 2
In the other cases, the duty is as below.
“0” period : “1” period = 1 : 1
Fig. 6.7.11 I²C clock contorol register
Address 00DB16
6-36
7220 Group User’s Manual