HD6432621 Hitachi, HD6432621 Datasheet - Page 736

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

21A.2.2 System Clock Control Register (SCKCR)
SCKCR is an 8-bit readable/writable register that performs ø 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—ø Clock Output Disable (PSTOP): In combination with the DDR of the applicable port,
this bit controls ø output. See section 21A.8, ø Clock Output Disable Function, for details.
Bit 7
PSTOP
0
1
Bits 6 to 4—Reserved: These bits are always read as 0 and cannot be modified.
Bit 3—Frequency Multiplication Factor Switching Mode Select (STCS): Selects the operation
when the PLL circuit frequency multiplication factor is changed.
Bit 3
STCS
0
1
692
Bit
Initial value :
R/W
High-Speed Mode,
Medium-Speed Mode
ø output (initial value)
Fixed high
Description
Specified multiplication factor is valid after transition to software standby mode
Specified multiplication factor is valid immediately after STC bits are rewritten
:
:
PSTOP
R/W
7
0
—
—
6
0
Sleep Mode
ø output
Fixed high
—
—
5
0
Description
—
—
4
0
Software Standby
Mode
Fixed high
Fixed high
STCS
R/W
3
0
SCK2
R/W
2
0
Hardware Standby
Mode
High impedance
High impedance
SCK1
R/W
1
0
(Initial value)
SCK0
R/W
0
0