SH7670 Datasheet, PDF (1198/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 29 Electrical Characteristics
29.2 Power-on/Power-off Sequence
The sequences for turning on and off power supplies are shown below together with recommended
values.
3.3 V power supply
tpwu
3.3 V power supply Min. voltage
1.2 V power supply
1.2 V power supply Min. voltage
tpwd
GND
tunc
Pins status undefined
Normal operating period
tunc
Pins status undefined
Figure 29.1 Power-on/Power-off Sequence
Table 29.2 Recommended Time for Power-on/Power-off Sequence
Item
Symbol
Min.
Max.
Unit
Time difference in turning on 3.3 V to 1.2 V
tpwu
power supplies
0

ms
Time difference in turning off 1.2 V to 3.3 V
tpwd
power supplies
0

ms
State undefined time
tunc

100
ms
Note:
The table shown above is recommended values, so they represent guidelines rather than
strict requirements.
The 3.3-V power supply (VCCQ_,, AV33, and DV33) should be turned on before the 1.2-V
power supply (VCC , VCC (PLL) , AV12, DV12, and UV12) is turned on. In addition, the 3.3-V
power supply should be turned off after the 1.2-V power supply is turned off. An undefined
time appears until the 1.2-V power supply reaches above the minimum voltage and after it
has reached below the minimum voltage. During these periods, pin and internal states
become undefined. Design the system so that these undefined states do not cause an
overall malfunction.
Rev. 1.00 Nov. 14, 2007 Page 1172 of 1262
REJ09B0437-0100