SH7713 Datasheet, PDF (824/904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 24 Electrical Characteristics
• Power-off order
1. In the reverse order of powering-on, first turn off the 1.5 V power, then turn off the 3.3 V
power within 1 ms. It is recommended that this interval will be as short as possible.
2. Pin states are undefined while only the 1.5 V power is off. The system design must ensure
that these undefined states do not cause erroneous system operation.
3. When the power is turned off, make sure that the voltage of the 1.5 V power is lower than
that of the 3.3 V power.
Waveforms and recommended times at power on/off are shown in Figure 24.1.
VccQ: 3.3 V power
VccQ (min) voltage
tpwu
Vcc: 1.5 V power
Vcc (min) voltage
Vcc/2 level voltage
tpwd
GND
tunc
States undefined
term
Normal operation term
Clock oscillation started
VccQ (min)
attain time
Vcc (min)
attain time
Oscillation settling time (10 ms)
Cancel the power-on reset and
go to normal operation
Figure 24.1 Power On/Off Sequence
Operation stopped
Recommended Power On/Off Times
Item
Symbol
Max. Permitted
Value
Unit
VccQ to Vcc power-on time interval
tpwu
1
ms
VccQ to Vcc power-off time interval
tpwd
1
ms
State undefined term
tunc
10
ms
Note:
The recommended times shown above do not require strict settings.
The state undefined term indicates that pins are at the power rising stage. The pin state is
stabilized at VccQ (min.) attain time. However, a power-on reset (RESETP) is accepted
successfully only after VccQ (min.) attain time and clock oscillation settling time. Set the
state undefined term less than 10 ms.
Rev.1.50 Aug. 30, 2006 Page 784 of 860
REJ09B0288-0150