UPD78F0138 NEC, UPD78F0138 Datasheet - Page 123

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

(4) Main OSC control register (MOC)
This register selects the operation mode of the X1 input clock.
This register is used to stop the X1 oscillator operation when the CPU is operating with the Ring-OSC clock.
Therefore, this register is valid only when the CPU is operating with the Ring-OSC clock.
MOC can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Address: FFA2H
Symbol
MOC
Cautions 1. Make sure that bit 1 (MCS) of the main clock mode register (MCM) is 1 before
MSTOP
MSTOP
<7>
0
1
After reset: 00H
2. To stop X1 oscillation when the CPU is operating on the subsystem clock, set bit
Figure 5-5. Format of Main OSC Control Register (MOC)
X1 oscillator operating
X1 oscillator stopped
setting MSTOP.
7 (MCC) of the processor clock control register (PCC) to 1 (setting by MSTOP is
not possible).
6
0
R/W
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16228EJ2V0UD
5
0
Control of X1 oscillator operation
4
0
3
0
2
0
1
0
0
0
123