upd78f0114hgb-8es-a Renesas Electronics Corporation., upd78f0114hgb-8es-a Datasheet - Page 100

• Manufacturer Part Number: upd78f0114hgb-8es-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

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Notes 1.
(2) Internal oscillation mode register (RCM)
100
f
f
f
f
f
f
X
X
X
X
X
XT
CPU Clock (f
/2
/2
/2
/2
/2
2
3
4
The fastest instruction can be executed in 2 clocks of the CPU clock in the 78K0/KC1+.
relationship between the CPU clock (f
This register sets the operation mode of internal oscillator.
This register is valid when “Can be stopped by software” is set for internal oscillator by the option byte, and the
high-speed system clock or subsystem clock is selected as the CPU clock. If “Cannot be stopped” is selected for
internal oscillator by the option byte, settings for this register are invalid.
RCM can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Address: FFA0H
Symbol
2.
3.
RCM
The main clock mode register (MCM) is used to set the CPU clock (high-speed system clock/internal
oscillation clock) (see Figure 5-4).
When crystal/ceramic oscillation is used
Setting is prohibited for the (A1) grade products.
Table 5-2. Relationship Between CPU Clock and Minimum Instruction Execution Time
CPU
)
Caution Make sure that bit 1 (MCS) of the main clock mode register (MCM) is 1 before setting
0.2 s
0.4 s
0.8 s
1.6 s
3.2 s
At 10 MHz Operation
RSTOP
7
0
0
1
After reset: 00H
Figure 5-3. Format of Internal Oscillation Mode Register (RCM)
RSTOP.
High-Speed System Clock
Internal oscillator oscillating
Internal oscillator stopped
6
0
Note 2
R/W
CHAPTER 5 CLOCK GENERATOR
CPU
0.125 s
0.25 s
0.5 s
1.0 s
2.0 s
At 16 MHz Operation
) and minimum instruction execution time is as shown in Table 5-2.
User’s Manual U16961EJ4V0UD
5
0
Minimum Instruction Execution Time: 2/f
Note 1
Internal oscillator oscillating/stopped
4
0
Note 2
At 240 kHz (TYP.) Operation At 32.768 kHz Operation
8.3 s (TYP.)
16.6 s (TYP.)
Setting prohibited
Setting prohibited
Setting prohibited
3
0
Internal Oscillation
Clock
Note 1
Note 3
2
0
CPU
122.1 s
1
0
Subsystem Clock
Therefore, the
RSTOP
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