2.12 Low Power Consumption Control Circuits (CPU Intermittent Operation Function, Oscillation Stabilization Wait
Time, Clock Multiplier Function)
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Chapter 2: Hardware
2.12.3 Detailed Register Descriptions
(1) LPMCR (Low Power Consumption Mode Control Register
s Register Configuration
s Bit Description
[Bit 7] STP
Writing ‘1’ to this bit causes transition to clock mode (CKSCR.MCS=0) or stop mode
(CKSCR.MCS=1). Writing ‘0’ to this bit has no effect. This bit can be cleared to ‘0’ by reset, and by
wake-up from watch mode and stop mode. Access to this bit is write-only, and the read value is
always ‘0.’
[Bit 6] SLP
Writing ‘1’ to this bit causes transition to sleep mode. Writing ‘0’ to this bit has no effect. This bit
can be cleared to ‘0’ by reset, and by wake-up from sleep mode or stop mode.
When ‘1’ is written simultaneously to the STP bit and SLP bit, the result is transition to watch mode
or stop mode. Access to this bit is write-only, and the read value is always ‘0.’
[Bit 5] SPL
When this bit is set to ‘0’ external pin levels are maintained while in watch mode or stop mode. A
value of ‘1’ means that external pins are placed in high-impedance state when in watch mode or stop
mode. This bit is cleared to ‘0’ at reset, and access is read-only.
[Bit 4] RST
Writing ‘0’ to this bit will generate an internal reset signal for 3 machine cycles. Writing ‘1’ to this
bit has no effect. The read value is always ‘1.’
[Bit 3] Reserved bit
Always write ‘1’ to this bit.
[Bits 2, 1] CG1, CG0
These bits determine the number of clock pause cycles in the CPU intermittent operation function.
These bits are initialized to ‘00’ by power-on reset or watchdog reset functions, but are not
initialized by any other reset sources. Access is read-only.
The CPU intermittent operation function allows the clock signal to be fed to the CPU intermittently
(with a given pause) for registers, internal memory, internal resources or external bus access. This
enables reduced power consumption by lowering the CPU execution speed while maintaining the
high speed clock feed to internal resources.
STP
SLP
SPL RST Reserved CG1
CG0 Reserved
Bit no.
Read/write
(W)
(W) (R/W)
(W)
(–)
(R/W) (R/W)
(–)
Initial value
(0)
(1)
(0)
(1)
Address : 0000A0H
7
6
5
4
3
2
1
0
LPMCR