upd78f0148m1gka1-9eu Renesas Electronics Corporation., upd78f0148m1gka1-9eu Datasheet - Page 439

• Manufacturer Part Number: upd78f0148m1gka1-9eu
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

21.1 Standby Function and Configuration
21.1.1 Standby function
Notes 1.
Caution The RSTOP setting is valid only when “Can be stopped by software” is set for internal oscillator by
Remark MSTOP: Bit 7 of the main OSC control register (MOC)
available.
(1) HALT mode
Operation
Mode
Reset
STOP
HALT
The standby function is designed to reduce the operating current of the system. The following two modes are
HALT instruction execution sets the HALT mode. In the HALT mode, the CPU operation clock is stopped. If the
X1 oscillator, internal oscillator, or subsystem clock oscillator is operating before the HALT mode is set, oscillation
of each clock continues. In this mode, the operating current is not decreased as much as in the STOP mode, but
the HALT mode is effective for restarting operation immediately upon interrupt request generation and carrying
out intermittent operations.
2.
3.
4.
Status
a mask option.
MCC:
RSTOP: Bit 0 of the internal oscillation mode register (RCM)
MCM0:
When “Cannot be stopped” is selected for internal oscillator by a mask option.
When “Can be stopped by software” is selected for internal oscillator by a mask option.
Operates using the CPU clock at STOP instruction execution.
Operates using the CPU clock at HALT instruction execution.
MSTOP = 0
Stopped
Oscillating
MCC = 0
Table 21-1. Relationship Between Operation Clocks in Each Operation Status
Bit 7 of the processor clock control register (PCC)
Bit 0 of the main clock mode register (MCM)
X1 Oscillator
MSTOP = 1
Stopped
MCC = 1
CHAPTER 21 STANDBY FUNCTION
Stopped
Oscillating
Note 1
User’s Manual U15947EJ3V1UD
Internal Oscillator
RSTOP = 0 RSTOP = 1
Oscillating
Note 2
Stopped
Subsystem
Oscillating
Oscillator
Clock
CPU Clock
Internal
oscillation
Note 3
Note 4
Release
After
Supplied to Peripherals
MCM0 = 0
Stopped
Stopped
Internal
oscillation
Prescaler Clock
X1
MCM0 = 1
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