RM0082
LS_I2C controller
Doc ID 018672 Rev 1
627/844
28.6.9 IC_SS_SCL_LCNT
register(0x018)
The IC_SS_SCL_LCNT is a 16 bit RW register which allows to set the low period of the SCL
clock for standard-speed mode. The IC_SS_SCL_LCNT bit assignments are given in
Note:
1
This register can be written only when the I
2
C controller is disabled, which corresponds to
the IC_ENABLE (
) register being set to ‘b0. Write at other times has no
effect.
2
This register must be set before any I
2
C bus transaction can take place in order to ensure
proper I/O timing.
:
Table 548.
IC_SS_SCL_HCNT sample calculations
I
2
C data rate - SS
(Kbps)
SCL clock
frequency
(MHz)
SCL high time
required min
(µs)
IC_SS_SCL_HCNT
(hex/decimal)
SCL high time
actual
(µs)
100
2
4
16‘h0008/’d8
4.00
100
6.6
4
16‘h001B/’d27
4.09
100
10
4
16‘h0028/’d40
4.00
100
75
4
16‘h012C/’d300
4.00
100
100
4
16‘h0190/’d400
4.00
100
125
4
16‘h01F4/’d500
4.00
100
1000
4
16’h0FA0/’d4000
4.00
Table 549.
IC_SS_SCL_LCNT register bit assignments
Bit
Name
Type
Reset
value
Description
[15:00]
IC_SS_SCL_LCNT
RW
16'h310
SCL clock low period count for standard
speed.
This 16 bit field states the SCL clock low
period count for standard speed. The
minimum valid value is 8, and hardware
prevents that a value less than this minimum
will be written (setting 8 if attempted).
Table 550.
IC_SS_SCL_LCNT sample calculations
I
2
C data rate - SS
(Kbps)
SCL clock
frequency
(MHz)
SCL low time
required min
(µs)
IC_SS_SCL_LCNT
(hex/decimal)
SCL low
timeactual
(µs)
100
2
4.7
16‘h000A/’d10
5.00
100
6.6
4.7
16‘h0020/’d32
4.85
100
10
4.7
16‘h002F/’d47
4.70
100
75
4.7
16’h0161/’d353
4.71
100
100
4.7
16‘h01D6/’d470
4.70