upd78f0103 Renesas Electronics Corporation., upd78f0103 Datasheet - Page 91

• Manufacturer Part Number: upd78f0103
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.3 Registers Controlling Clock Generator
(1) Processor clock control register (PCC)
The following six registers are used to control the clock generator.
• Processor clock control register (PCC)
• Ring-OSC mode register (RCM)
• Main clock mode register (MCM)
• Main OSC control register (MOC)
• Oscillation stabilization time counter status register (OSTC)
• Oscillation stabilization time select register (OSTS)
Note The setting of (A1) grade products and (A2) grade products is prohibited.
Remarks 1. MCM0: Bit 0 of the main clock mode register (MCM)
This register sets the division ratio of the CPU clock.
PCC can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Address: FFFBH
Symbol
PCC
2. f
3. f
4. f
X
R
XP
: Main system clock oscillation frequency (X1 input clock oscillation frequency or Ring-OSC clock
: Ring-OSC clock oscillation frequency
: X1 input clock oscillation frequency
PCC2
oscillation frequency)
7
0
0
0
0
0
1
After reset: 00H
Figure 5-2. Format of Processor Clock Control Register (PCC)
Other than above
PCC1
6
0
0
0
1
1
0
R/W
CHAPTER 5 CLOCK GENERATOR
PCC0
User’s Manual U15836EJ5V0UD
5
0
0
1
0
1
0
f
f
f
f
f
Setting prohibited
X
X
X
X
X
/2
/2
/2
/2
2
3
4
4
0
3
0
CPU clock selection (f
f
f
Setting prohibited
Setting prohibited
Setting prohibited
R
R
/2
Note
MCM0 = 0
PCC2
2
CPU
PCC1
)
f
f
f
f
f
1
XP
XP
XP
XP
XP
/2
/2
/2
/2
2
3
4
MCM0 = 1
PCC0
0
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