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MB90570 Series
19. Low-power Consumption (Standby) Mode
The F2MC-16LX has the following CPU operating mode configured by selection of an operating clock and clock
operation control.
Clock mode
PLL clock mode : A mode in which the CPU and peripheral equipment are driven by PLL-multiplied oscillation
clock (HCLK).
Main clock mode: A mode in which the CPU and peripheral equipment are driven by divided-by-2 of the
oscillation clock (HCLK).
The PLL multiplication circuits stops in the main clock mode.
CPU intermittent operation mode
The CPU intermittent operation mode is a mode for reducing power consumption by operating the CPU
intermittently while external bus and peripheral functions are operated at a high-speed.
Hardware standby mode
The hardware standby mode is a mode for reducing power consumption by stopping clock supply to the CPU
by the low-power consumption control circuit, stopping clock supplies to the CPU and peripheral functions
(timebase timer mode), and stopping oscillation clock (stop mode, hardware standby mode). Of these modes,
modes other than the PLL clock mode are power consumption modes.
(1) Register Configuration
Clock select register (CKSCR)
Address
0000A1H
bit 7
bit 0
SCM
MCM
WS1
WS0
SCS
MCS
CS1
CS0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
............
(LPMCR)
R
R/W
Address
0000A0H
bit 15
bit 8
STP
SLP
SPL
RST
TMD
CG1
CG0
SSR
(CKSCR)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
W
R/W
W
R/W
W
R/W
............
R/W : Readable and writable
R : Read only
W : Write only
Low-power consumption mode control register (LPMCR)
Initial value
00011000 B
Initial value
11111100 B