156
Chapter 4
Clock Generator
Preliminary User’s Manual U17566EE1V2UM00
(5)
ICC - IIC clock control register
The 8-bit ICC register determines the I
2
C clock source for IICLK.
Access
This register can be read/written in 8-bit units.
Writing to this register is protected by a special sequence of instructions.
Please refer to
“PHCMD - Command protection register” on page 140
for
details.
Address
FFFF F838
H
.
Initial Value
00
H
. The register is cleared by any reset.
Note
On release of WATCH, Sub-WATCH and STOP mode, IICSEL1 is cleared—the
main oscillator is selected as the I
2
C clock source.
Pay attention if PSM.OSCDIS = 1 before entering any of the above power save
modes, because the main oscillator will be disabled. Therefore the I
2
C
interface will have no clock supply after power save mode release.
7
6
5
4
3
2
1
0
0
0
a
a)
These bits must not be altered.
0
a
0
a
0
0
IICSEL1
0
a
R
b
b)
These bits may be written, but write is ignored.
R/W
R/W
R/W
R
b
R
b
R/W
R/W
Table 4-17
ICC register contents
Bit position
Bit name
Function
1
IICSEL1
Clock source for IICLK:
IICSEL1
Clock source
0
Main oscillator
1
PLL
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