ST72321B STMICROELECTRONICS [STMicroelectronics], ST72321B Datasheet - Page 165

• Manufacturer Part Number: ST72321B
• Description: 64/44-pin 8-bit MCU with 32 to 60K Flash/ROM, ADC, five timers, SPI, SCI, I2C interface
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

COMMUNICATION INTERFACE CHARACTERISTICS (Cont’d)
The following table gives the values to be written in
the I2CCCR register to obtain the required I
SCL line frequency.
Table 28. SCL Frequency Table
Legend:
R
f
NA = Not achievable
Note:
– For speeds around 200 kHz, achieved speed can have ±5% tolerance
– For other speed ranges, achieved speed can have ±2% tolerance
The above variations depend on the accuracy of the external components used.
SCL
P
= External pull-up resistance
(kHz)
f
400
300
200
100
= I
SCL
50
20
2
C speed
R
P
=3.3kΩ
5Fh
83h
10h
24h
NA
NA
V
DD
= 4.1 V
R
P
=4.7kΩ
5Fh
83h
10h
24h
NA
NA
f
CPU
=4 MHz.
R
P
=3.3kΩ
5Fh
83h
10h
24h
NA
NA
V
DD
= 5 V
2
C
R
P
=4.7kΩ
5Fh
83h
10h
24h
NA
NA
I2CCCR Value
R
P
=3.3kΩ
8Ah
4Ch
FFh
83h
85h
24h
V
DD
= 4.1 V
R
P
=4.7kΩ
4Ch
FFh
85h
89h
23h
83
f
CPU
=8 MHz.
R
P
=3.3kΩ
8Ah
4Ch
FFh
83h
85h
24h
V
DD
= 5 V
R
P
165/187
=4.7kΩ
8Ah
4Ch
FFh
83h
85h
23h