SH7730 Datasheet, PDF (1104/1188 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7780 Series

Section 33 Electrical Characteristics
33.2 Power-On and Power-Off Order
(1) Order of turning on 1.2 V power (V_CC, V_CC_PLL1, and V_CC_PLL2) and 3.3 V power
(V_CCQ, AV_CC)
• First turn on the 3.3 V power, then turn on the 1.2 V power within 1 ms. This interval should
be as short as possible. The system design must ensure that the states of pins or undefined
period of an internal state do not cause erroneous system operation.
• Do not allow the voltage of the 1.2 V supply system to be above that of the 3.3 V supply
system.
• Until voltage is applied to all power supplies and a low level is input to the RESETP pin,
internal circuits remain unsettled, and so pin states are also undefined. The system design must
ensure that these undefined states do not cause erroneous system operation.
Waveforms at power-on are shown in the following figure.
VccQ, AVcc: 3.3 V power
VccQ, AVcc (min.) voltage
GND
RESETP
t_PWU
t_UNC
Pins states undefined
Turn on power while RESETP is low in advance
Vcc, Vcc_PLL1, Vcc_PLL2: 1.2 V power
Vcc, Vcc_PLL1, Vcc_PLL2 (min.) voltage
Vcc/2 level voltage
Normal operation period
Other pins*
Pins states undefined
Power-on reset state
Note: * Except power/GND, clock related, and analog pins.
Table 33.2 Recommended Timing in Power-On
Item
Symbol Maximum Value Unit
Time difference between the power-on of (V_CCQ, AV_CC) and t_PWU
1
ms
(V_CC, V_CC_PLL1, V_CC_PLL2) levels
Time over which the internal state is undefined
t_UNC
100
ms
Note: * The table shown above is recommended values, so they represent guidelines rather
than strict requirements.
Rev. 1.00 Sep. 19, 2007 Page 1056 of 1136
REJ09B0359-0100