Fujitsu F2MC-16LX Hardware Manual page 36

CHAPTER 1 OVERVIEW OF MB90470
❍ Note on operations during PLL clock mode
If the PLL clock mode is selected, the microcontroller attempt to be working with the self-
oscillating circuit even when there is no external oscillator or external clock input is stopped.
Performance of this operation, however, cannot be guaranteed.
I Notes on handling the power supply
❍ Stabilizing the power supply
Even in the range of V
a misoperation.
variation (P-P value) in the commercial frequency (50/60 MHz) must be 10% of the standard
V value or lower, or the transient variation must be 0.1 V/ms in instantaneous variation
CC
including power supply switching.
❍ Notes on using two power supplies
The MB90470 series usually uses the 3-V power supply as the main power source. With V
3 V and V
P37/A07/PWC1, P40/A08/SIN2 to P47/A15/OUT5, and P70/SIN0 to P77/SDA for the 5-V power
supply separately from the 3-V power supply at all operation mode. Note, however, that the
analog power supply of the A/D converter (e.g., AV
power supplies.
❍ Crystal oscillation circuit using low voltage
At voltages below 2.0 V, some external crystal oscillators may not work when the power supply
is turned on. Thus, Fujitsu recommends using the external clock.
❍ To use this product, which is two system products, as a single system, use it under the
conditions of X0A = V
❍ For serial writing to flash memory, always make sure that the operating voltage V
between 3.13 V and 3.6 V.
For normal writing to flash memory, always make sure that the operating voltage V
between 3 V and 3.6 V.
20
Figure 1.7-1 Use of external clock
power supply voltage, a rapid change in the power supply may cause
CC
Fujitsu recommends that, as a reference for stabilization, the V
5 = 5 V, however, it can interface with P20/A16 to P27/A23/PPG3, P30/A00/AIN0 to
CC
and X1A = OPEN.
SS
X0
OPEN X1
and AV
CC
CC
) can be used only as 3-V
SS
CC
CC
ripple
3 =
CC
is
is