88
CHAPTER 3 CLOCK GENERATOR AND CONTROLLER
[Example]
The output from the divide-by-two frequency circuit can be selected as the source clock by
setting the CHC bit of the gear control register to 1. Setting the CHC bit to 0 selects the clock
having the same cycle as the clock generated from the oscillation circuit. Since the source
clock is changed, the CPU and peripheral systems change simultaneously.
[Example]
Figure 3.9.2 is a timing chart for clock selection
LDI:20
#GCR,R2
LDI:8
#11111110b,R1
; CCK=11,PCK=11,CHC=0
STB
R1.@R2
; CPU clock=1/8f, Peripheral clock=1/8f, f=direct
LDI:8
#01111010b,R1
; CCK=01,PCK=10,CHC=0
STB
R1,@R2
; CPU clock=1/2f, Peripheral clock=1/4f, f=direct
LDI:8
#00111010b,R1
; CCK=00,PCK=10,CHC=0
STB
R1,@R2
; CPU clock=f, Peripheral clock=1/4f, f=direct
LDI:8
#00110010b,R1
; CCK=00,PCK=00,CHC=0
STB
R1,@R2
; CPU clock=f, Peripheral clock=f, f=direct
LDI:8
#10110010b,R1
; CCK=10,PCK=00,CHC=0
STB
R1,@R2
; CPU clock=1/4f, Peripheral clock=f, f=direct
LDI:8
#01110001b,R1
; CCK=01,PCK=00,CHC=1
LDI:20
#GCR,R2
STB
R1,@R2
; CPU clock=1/2f, Peripheral clock=f, f=1/2xtal
LDI:8
#00110011b,R1
; CCK=00,PCK=00,CHC=1
STB
R1,@R2
; CPU clock=f, Peripheral clock=f, f=1/2xtal
LDI:8
#00110010b,R1
; CCK=00,PCK=00,CHC=0
STB
R1,@R2
; CPU clock=f, Peripheral clock=f, f=direct
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 ...
Page 460: ......
Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...