upd78f0114m6gb-8es Renesas Electronics Corporation., upd78f0114m6gb-8es Datasheet - Page 337

• Manufacturer Part Number: upd78f0114m6gb-8es
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

17.1 Standby Function and Configuration
17.1.1 Standby function
Notes 1.
Caution The RSTOP setting is valid only when “Can be stopped by software” is set for Ring-OSC by a mask
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, Ring-OSC 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
option.
MCC:
RSTOP: Bit 0 of the Ring-OSC mode register (RCM)
MCM0:
When “Cannot be stopped” is selected for Ring-OSC by a mask option.
When “Can be stopped by software” is selected for Ring-OSC 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 17-1. 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 17 STANDBY FUNCTION
Stopped
Oscillating
Note 1
Ring-OSC Oscillator
User’s Manual U16227EJ3V0UD
RSTOP = 0 RSTOP = 1
Oscillating
Note 2
Stopped
Subsystem
Oscillating
Oscillator
Clock
CPU Clock
Ring-OSC
Note 3
Note 4
Release
After
Supplied to Peripherals
MCM0 = 0
Stopped
Stopped
Ring-OSC
Prescaler Clock
X1
MCM0 = 1
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