Fujitsu 8FX User Manual

MB95630H Series
MN702-00009-2v0-E FUJITSU SEMICONDUCTOR LIMITED 29
CHAPTER 3 CLOCK CONTROLLER
3.3 Registers
3.3.2 PLL Control Register (PLLC)
The PLL control register (PLLC) controls the main CR PLL clock multiplication
rate settings.
■ Register Configuration
■ Register Functions
[bit7] MPEN: Main CR PLL clock enable bit
This bit enables or disables the main CR PLL clock.
When SCS[2:0] are set to "0b111", this bit is automatically set to "1".
When SCS[2:0] or SCM[2:0] are set to "0b111", writing "0" to this bit has no effect on operation.
This bit is automatically set to "0" when the clock mode transits from one mode to another mode except main
CR PLL clock mode.
When the current clock mode is subclock mode or sub-CR clock mode, writing "1" to this bit has no effect on
operation.
[bit6:5] MPMC[1:0]: Main CR PLL clock multiplication rate select bits
These bits select a main CR PLL clock multiplication rate.
The settings of these bits can be modified only when the main CR PLL clock is stopped. Thus these bits can
be modified in main clock mode, main CR clock mode, subclock mode or sub-CR clock mode.
Note: When SCS[2:0] or SCM[2:0] are set to "0b111", writing values to MPMC[1:0] is prohibited.
[bit4] MPRDY: Main CR PLL clock oscillation stabilization bit
This bit indicates whether the main CR PLL clock oscillation is ready.
[bit3:0] Undefined bits
Their read values are always "0". Writing values to these bits has no effect on operation.
bit 7 6 5 4 3 2 1 0
Field MPEN MPMC1 MPMC0 MPRDY — — — —
Attribute R/W R/W R/W R — — — —
Initial value 0 0 0 X 0 0 0 0
bit7 Details
Writing "0" Disables the main CR PLL clock.
Writing "1" Enables the main CR PLL clock.
bit6:5 Details
Writing "00" Main CR clock × 2
Writing "01" Main CR clock × 2.5
Writing "10" Main CR clock × 3
Writing "11" Main CR clock × 4
bit4 Details
Reading "0"
Indicates that main CR PLL clock is in the oscillation stabilization wait state or that the main CR
PLL clock oscillation has stopped.
Reading "1" Indicates that the main CR PLL clock oscillation wait time is over.

Fujitsu 8FX Specifications

General

Brand	Fujitsu
Model	8FX
Category	Computer Hardware
Language	English