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FUJITSU MICROELECTRONICS
PROPRIETARY AND CONFIDENTIAL
MB86R01 DATA SHEET
8.3.
Precautions at Power On
8.3.1.
Recommended Power On/Off Sequence
Follow the power on/off sequence as shown below:
<ON>: VDDI (internal and PLLVDD)
→ DDRVDE (external) → VDDE (external) → Signal
<OFF>: Signal
→ VDDE (external) → DDRVDE (external) → VDDI (internal and PLLVDD)
VDDI
VDDE
DDRVDE
Figure 8-1
Recommended Power On/Off Sequence (1)
There is no limitation on the sequence of power on/off of VDDI, VDDE, and DDRVDE if the following
Do not apply VDDE and DDRVDE (external) continuously more than 1 second when VDDI (internal)
is off.
VDDE
1 sec. or less
VDDI
1 sec. or less
DDRVDE
Figure 8-2
Recommended Power On/Off Sequence (2)
Perform power on/off for VREF according to the DDR2-SDRAM regulation.
Perform power on/off so that power for PLLVDD (PLL) does not exceed VDDI.
Turn on all power. Turning on only a part of them is prohibited.
CMOS IC becomes unstable immediately after power-on so that proceed reset immediately.
Set the reset pins (XTRST and XRST) to Low when power-on.
Input clock to CLK pin immediately after power-on.
It requires at least 100 clocks (input clock to CLK pin) for the reset signal "L" applied to the XRST pin to
be transmitted to all internal circuits.