Fujitsu FR81S User Manual
CHAPTER 5: CLOCK
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK
FUJITSU SEMICONDUCTOR CONFIDENTIAL
81
5.7. Operations during MDI Communications
Operations during MDI communications are shown.
The main oscillation is controlled so as not to be stopped during MDI communications even if the stop mode
is transited to.
Moreover, (E_DBCR.PLOCK=1) is controlled so that the PLL reference clock is supplied even if
CSELR.PCEN is cleared while communicating the MDI high speed. The value of the register related to PLL
is maintained and not updated. However, when software sets PLLCR.PCEN=0, the value of the register
related to PLL can be freely updated (write).
When a value set to the register related to PLL last time and a different value are written and the PLL/SSCG
clock oscillation permission is assumed to be effective (CSELR.PCEN=1), the frequency of the PLL clock is
not updated. (PLL : because it maintains the locked status. )
Normally, always write the same value in the register related to PLL usually. When you change the setting
value in the debug, monitor the value of E_DBCR.PLOCK and rewrite the register related to PLL in the status
of E_DBCR.PLOCK =0.
* The register related to PLL is as follows.
⋅
CCPSDIVR.PODS
⋅
CCPLLFBR.IDIV
⋅
PLLCR.PDS
MB91520 Series
MN705-00010-1v0-E
242