Datasheet

ST72321Rx ST72321ARx ST72321Jx
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COMMUNICATION INTERFACE CHARACTERISTICS (Cont’d)
The following table gives the values to be written in
the I2CCCR register to obtain the required I
2
C
SCL line frequency.
Table 28. SCL Frequency Table
Legend:
R
P
= External pull-up resistance
f
SCL
= I
2
C speed
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.
f
SCL
(kHz)
I2CCCR Value
f
CPU
=4 MHz. f
CPU
=8 MHz.
V
DD
= 4.1 V V
DD
= 5 V V
DD
= 4.1 V V
DD
= 5 V
R
P
=3.3kΩ R
P
=4.7kΩ R
P
=3.3kΩ R
P
=4.7kΩ R
P
=3.3kΩ R
P
=4.7kΩ R
P
=3.3kΩ R
P
=4.7kΩ
400 NA NA NA NA 83h 83 83h 83h
300 NA NA NA NA 85h 85h 85h 85h
200 83h 83h 83h 83h 8Ah 89h 8Ah 8Ah
100 10h 10h 10h 10h 24h 23h 24h 23h
50 24h 24h 24h 24h 4Ch 4Ch 4Ch 4Ch
20 5Fh 5Fh 5Fh 5Fh FFh FFh FFh FFh