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RL78/G1A CHAPTER 18 STANDBY FUNCTION
Table 18-1. Operating Statuses in HALT Mode (1/2)
When HALT Instruction Is Executed While CPU Is Operating on Main System Clock HALT Mode Setting
Item
When CPU Is Operating on
High-speed On-chip Oscillator
Clock (f
IH)
When CPU Is Operating on
X1 Clock (f
X)
When CPU Is Operating on
External Main System Clock
(f
EX)
System clock Clock supply to the CPU is stopped
fIH Operation continues (cannot
be stopped)
Operation disabled
fX Operation continues (cannot
be stopped)
Cannot operate
Main system clock
fEX
Operation disabled
Cannot operate Operation continues (cannot
be stopped)
fXT
Subsystem clock
fEXS
Status before HALT mode was set is retained
fIL Set by bits 0 (WDSTBYON) and 4 (WDTON) of option byte (000C0H), and WUTMMCK0 bit of
subsystem clock supply mode control register (OSMC)
• WUTMMCK0 = 1: Oscillates
• WUTMMCK0 = 0 and WDTON = 0: Stops
• WUTMMCK0 = 0, WDTON = 1, and WDSTBYON = 1: Oscillates
• WUTMMCK0 = 0, WDTON = 1, and WDSTBYON = 0: Stops
CPU
Code flash memory
Data flash memory
RAM
Operation stopped
Port (latch) Status before HALT mode was set is retained
Timer array unit
Real-time clock (RTC)
12-bit interval timer
Operable
Watchdog timer See CHAPTER 10 WATCHDOG TIMER
Clock output/buzzer output
A/D converter
Serial array unit (SAU)
Serial interface (IICA)
Multiplier and divider/multiply-
accumulator
DMA controller
Power-on-reset function
Voltage detection function
External interrupt
Key interrupt function
High-speed CRC
Operable
CRC
operation
function
General-purpose
CRC
Operation stopped
RAM parity error detection
function
RAM guard function
SFR guard function
Illegal-memory access
detection function
Operation stopped
Remark Operation stopped: Operation is automatically stopped before switching to the HALT mode.
Operation disabled: Operation is stopped before switching to the HALT mode.
f
IH: High-speed on-chip oscillator clock fEX: External main system clock
fIL: Low-speed on-chip oscillator clock fXT: XT1 clock
fX: X1 clock fEXS: External subsystem clock
R01UH0305EJ0200 Rev.2.00 728
Jul 04, 2013