I
2
C Interface
27-4
Freescale Semiconductor
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
27.2.3
I
2
C Control Register (I2CR)
I2CR enables the I
2
C module and the I
2
C interrupt. It also contains bits that govern operation as a slave or
a master.
IPSBAR
Offset:
0x00_0304 (I2FDR)
Access: User read/write
7
6
5
4
3
2
1
0
R
0
0
IC
W
Reset:
0
0
0
0
0
0
0
0
Figure 27-3. I
2
C Frequency Divider Register (I2FDR)
Table 27-3. I2FDR Field Descriptions
Field
Description
7–6
Reserved, must be cleared.
5–0
IC
I
2
C clock rate. Prescales the clock for bit-rate selection. The serial bit clock frequency is equal to the internal bus
clock divided by the divider shown below. Due to potentially slow I2C_SCL and I2C_SDA rise and fall times, bus
signals are sampled at the prescaler frequency.
IC
Divider
IC
Divider IC
Divider
IC
Divider
0x00
28
0x10
288
0x20
20
0x30
160
0x01
30
0x11
320
0x21
22
0x31
192
0x02
34
0x12
384
0x22
24
0x32
224
0x03
40
0x13
480
0x23
26
0x33
256
0x04
44
0x14
576
0x24
28
0x34
320
0x05
48
0x15
640
0x25
32
0x35
384
0x06
56
0x16
768
0x26
36
0x36
448
0x07
68
0x17
960
0x27
40
0x37
512
0x08
80
0x18
1152
0x28
48
0x38
640
0x09
88
0x19
1280
0x29
56
0x39
768
0x0A
104
0x1A
1536
0x2A
64
0x3A
896
0x0B
128
0x1B
1920
0x2B
72
0x3B
1024
0x0C
144
0x1C
2304
0x2C
80
0x3C
1280
0x0D
160
0x1D
2560
0x2D
96
0x3D
1536
0x0E
192
0x1E
3072
0x2E
112
0x3E
1792
0x0F
240
0x1F
3840
0x2F
128
0x3F
2048
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60