86
CHAPTER 5 CLOCKS
5.1
Clocks
The clock generation block controls the operation of the internal clock that controls
operation of the CPU and peripheral functions. This internal clock is called the machine
clock. One internal clock cycle is called one machine cycle. Other clocks include a
clock generated by source oscillation, called an oscillation clock, and a clock generated
by the internal PLL oscillation, called a PLL clock.
■
Clocks
The clock generation block contains the oscillation circuit that generates the oscillation clock. An external
oscillator is attached to this circuit. The oscillation clock can also be supplied by inputting an external clock
to the clock generation block. The clock generation block also contains the PLL clock multiplier circuit,
which generates six clocks whose frequencies are multiples of the oscillation clock frequency. The clock
generation block controls the oscillation stabilization wait time and PLL clock multiplication as well as
internal clock operation by changing the clock with a clock selector.
●
Oscillation clock (HCLK)
The oscillation clock is generated either from an external oscillator attached to the oscillation circuit or by
the input of an external clock.
●
Main clock (MCLK)
The main clock, whose frequency is the oscillation clock frequency divided by 2, supplies the clock input
to the time-base timer and the clock selector.
●
PLL clock (PCLK)
The PLL clock is obtained by multiplying the oscillation clock frequency with the internal PLL clock
multiplier circuit (PLL oscillation circuit). Selection can be made from among six different PLL clocks.
●
Clock Modulator (CLOMO)
The clock modulator reduces the electromagnetic interference - EMI, by spreading the spectrum of the
clock signal over a wide range of different frequencies. The modulator provides two operation modes: 1)
phase modulation mode and 2) frequency modulation mode. Please refer to "CHAPTER 6 CLOCK
MODULATOR" for more detail.
Summary of Contents for MB90390 Series
Page 2: ......
Page 4: ......
Page 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
Page 18: ...xiv ...
Page 132: ...104 CHAPTER 5 CLOCKS ...
Page 152: ...124 CHAPTER 6 CLOCK MODULATOR ...
Page 210: ...182 CHAPTER 11 TIME BASE TIMER ...
Page 218: ...190 CHAPTER 12 WATCHDOG TIMER ...
Page 264: ...236 CHAPTER 14 16 BIT RELOAD TIMER WITH EVENT COUNT FUNCTION ...
Page 274: ...246 CHAPTER 15 WATCH TIMER ...
Page 306: ...278 CHAPTER 17 DTP EXTERNAL INTERRUPTS ...
Page 338: ...310 CHAPTER 18 8 10 BIT A D CONVERTER ...
Page 364: ...336 CHAPTER 19 UART0 UART1 ...
Page 398: ...370 CHAPTER 20 UART2 UART3 Figure 20 5 2 ORE Set Timing Receive data RDRF ORE ...
Page 432: ...404 CHAPTER 20 UART2 UART3 ...
Page 482: ...454 CHAPTER 22 SERIAL I O ...
Page 560: ...532 CHAPTER 24 STEPPING MOTOR CONTROLLER ...
Page 582: ...554 CHAPTER 27 ROM MIRRORING MODULE ...
Page 632: ...604 CHAPTER 29 EXAMPLES OF SERIAL PROGRAMMING CONNECTION ...
Page 722: ...694 APPENDIX ...
Page 723: ...695 INDEX The index follows on the next page This is listed in alphabetic order ...
Page 740: ......