upd78f0103hmca1-5a4-a Renesas Electronics Corporation., upd78f0103hmca1-5a4-a Datasheet - Page 86

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

(3) Main clock mode register (MCM)
86
This register sets the CPU clock (high-speed system clock/internal oscillation clock).
MCM can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Address: FFA1H
Symbol
MCM
Note Bit 1 is read-only.
Caution When the internal oscillation clock is selected as the clock to be supplied to the
MCM0
MCS
7
0
0
1
0
1
After reset: 00H
CPU, the divided clock of the internal oscillator output (f
peripheral hardware (f
Operation of the peripheral hardware with the internal oscillation clock cannot be
guaranteed. Therefore, when the internal oscillation clock is selected as the clock
supplied to the CPU, do not use peripheral hardware.
peripheral hardware before switching the clock supplied to the CPU from the high-
speed system clock to the internal oscillation clock.
following peripheral hardware can be used when the CPU operates on the internal
oscillation clock.
• Watchdog timer
• Clock monitor
• 8-bit timer H1 when f
• Peripheral hardware with an external clock selected as the clock source
Figure 5-4. Format of Main Clock Mode Register (MCM)
Operates with internal oscillation clock
Operates with high-speed system clock
Internal oscillation clock
High-speed system clock
(Except when the external count clock of TM00 is selected (TI000 valid edge))
6
0
R/W
CHAPTER 5 CLOCK GENERATOR
Note
User’s Manual U16846EJ3V0UD
5
0
X
R
= 240 kHz (TYP.)).
/2
7
Selection of clock supplied to CPU
is selected as the count clock
4
0
CPU clock status
3
0
2
0
Note, however, that the
MCS
<1>
In addition, stop the
X
) is supplied to the
MCM0
<0>