82
CHAPTER 3 CLOCK GENERATOR AND CONTROLLER
3.6
Gear Control Register (GCR)
The gear control register (GCR) controls the gear functions of the CPU and peripheral
clocks.
■
Configuration of the Gear Control Register (GCR)
The configuration of the gear control register (GCR) is shown below:
■
Bit Functions of the Gear Control Register (GCR)
[bit 15,14] CCK1, 0
These bits specify the CPU gear cycle. The bits and the cycles selected by the bits have the
relationships shown in Table 3.6.1. These bits are initialized by resetting.
PLL: PLL oscillation frequency
Source oscillation: Input frequency from X0
[bit 13] DBLAK
This bit indicates the clock doubler operation mode. Since the bit is read only, a write
attempt is ignored. This bit is initialized by resetting.
Bus frequency switching involves a time lag. This bit can be used to check whether
operation has actually been changed. This model does not support the clock doubler
function.
15
14
13
12
11
10
09
08
00000484
H
CCK1
CCK0
DBLAK DBLON PCK1
PCK0
CHC
110011-1
R/W
Initial value
Access
Table 3.6-1 CPU Machine Clock
CCK1
CCK0
CHC
CPU machine clock
0
0
0
PLL
× 1
0
1
0
PLL
×
1/2
1
0
0
PLL
×
1/4
1
1
0
PLL
×
1/8
0
0
1
Source oscillation × 1
/
2
0
1
1
Source oscillation ×
1/2
×
1/2
1
0
1
Source oscillation
×
1/2
×
1/4
1
1
1
Source oscillation
×
1/2
×
1/8 [Initial value]
Summary of Contents for MB91F109
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...
Page 4: ......
Page 10: ...vi ...
Page 24: ...xx ...
Page 96: ...72 CHAPTER 2 CPU ...
Page 224: ...200 CHAPTER 4 BUS INTERFACE ...
Page 234: ...210 CHAPTER 5 I O PORTS ...
Page 268: ...244 CHAPTER 9 U TIMER ...
Page 290: ...266 CHAPTER 10 UART ...
Page 314: ...290 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 322: ...298 CHAPTER 13 BIT SEARCH MODULE ...
Page 392: ...368 CHAPTER 16 FLASH MEMORY ...
Page 432: ...408 APPENDIX E Instructions F Table E 2 Instruction Formats OP rel11 5 11 ...
Page 448: ...424 APPENDIX E Instructions ...
Page 449: ...425 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 458: ...434 INDEX ...
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Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...