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16.1.2
Register Configuration
The clock pulse generator is controlled by SCKCR and LPWRCR. Table 16-1 shows the register
configuration.
Table 16-1 Clock Pulse Generator Register
Name
Abbreviation
R/W
Initial Value
Address*
System clock control register
SCKCR
R/W
H'00
H'FDE6
Low-power control register
LPWRCR
R/W
H'00
H'FDEC
Note:* Lower 16 bits of the address.
16.2
Register Descriptions
16.2.1
System Clock Control Register (SCKCR)
7
PSTOP
0
R/W
6
—
0
R/W
5
—
0
—
4
—
0
—
3
—
0
R/W
0
SCK0
0
R/W
2
SCK2
0
R/W
1
SCK1
0
R/W
Bit
Initial value
R/W
:
SCKCR is an 8-bit readable/writable register that performs clock output control and medium-
speed mode control.
SCKCR is initialized to H'00 by a reset and in hardware standby mode. It is not initialized in
software standby mode.
Bit 7— Clock Output Disable (PSTOP): Controls output.
Description
Bit 7
High–Speed Mode
Software Standby
Hardware
PSTOP
Medium-Speed Mode
Sleep Mode
Mode, WatchStandby Mode
0
output (initial value)
output
Fixed high
High impedance
1
Fixed high
High impedance
Bits 6 and 3—Reserved: This bit can be read or written to, but only 0 should be written.
Bits 5 and 4—Reserved: Read-only bits, always read as 0.