upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 87

• Manufacturer Part Number: upd78f0103hmca1-5a4-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(4) Main OSC control register (MOC)
(5) Oscillation stabilization time counter status register (OSTC)
Caution Waiting for the oscillation stabilization time is not required when the external RC oscillation
This register selects the operation mode of the high-speed system clock.
This register is used to stop the high-speed system clock oscillator operation when the CPU is operating with the
internal oscillation clock. Therefore, this register is valid only when the CPU is operating with the internal
oscillation clock.
MOC can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
This is the status register of the high-speed system clock oscillation stabilization time counter. If the internal
oscillation clock is used as the CPU clock, the high-speed system clock oscillation stabilization time can be
checked.
OSTC can be read by a 1-bit or 8-bit memory manipulation instruction.
When reset is released (reset by RESET input, POC, LVI, clock monitor, and WDT), the STOP instruction,
MSTOP = 1 clear OSTC to 00H.
Address: FFA2H
Symbol
MOC
clock is selected as the high-speed system clock by the option byte. Therefore, the CPU clock
can be switched without reading the OSTC value.
Caution Make sure that bit 1 (MCS) of the main clock mode register (MCM) is 0 before setting
MSTOP
MSTOP
<7>
0
1
After reset: 00H
MSTOP.
Figure 5-5. Format of Main OSC Control Register (MOC)
High-speed system clock oscillator operating
High-speed system clock oscillator stopped
6
0
R/W
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16846EJ3V0UD
5
0
Control of high-speed system clock oscillator operation
4
0
3
0
2
0
1
0
0
0
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