st72f321r STMicroelectronics, st72f321r Datasheet - Page 166

• Manufacturer Part Number: st72f321r
• Description: 64/44-pin 8-bit Mcu With 32 To 60k Flash/rom, Adc, Five Timers, Spi, Sci, I2c Interface
• Manufacturer: STMicroelectronics

ST72321
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 27. 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.
166/189
SCL
P
= External pull-up resistance
(kHz)
f
400
300
200
100
= I
SCL
50
20
2
C speed
R
P
=3.3k
5Fh
83h
10h
24h
NA
NA
V
DD
= 4.1 V
R
P
=4.7k
83h
10h
24h
5Fh
NA
NA
f
CPU
=4 MHz.
R
P
=3.3k
5Fh
83h
10h
24h
NA
NA
V
DD
= 5 V
2
C
R
P
=4.7k
5Fh
83h
10h
24h
NA
NA
I2CCCR Value
R
P
=3.3k
8Ah
4Ch
FFh
83h
85h
24h
V
DD
= 4.1 V
R
P
=4.7k
4Ch
FFh
85h
89h
23h
83
f
CPU
=8 MHz.
R
P
=3.3k
8Ah
4Ch
FFh
83h
85h
24h
V
DD
= 5 V
R
P
=4.7k
8Ah
4Ch
FFh
83h
85h
23h