SH7720 Datasheet, PDF (1368/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 38 Electrical Characteristics
38.2 Power-On and Power-Off Order
• Order of turning on 1.5 V power (V_CC, V_CC_PLL1, V_CC_PLL2, and V_CC_RTC), 1.8 V/3.3 V
power (V_CCQ1), and 3.3V power (V_CCQ, V_CC_RTC, AV_CC, AV_CC_USB
 First turn on the 3.3 V power and 3.3 V/1.8 V power, then turn on the 1.5 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.
 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, VccQ_RTC, AVcc, AVcc_USB: 3.3 V power
VccQ1: 1.8 V/3.3V power
VccQ, VccQ1, VccQ_RTC, AVcc, AVcc_USB (min.) power
GND
RESETP
t_PWU
t_UNC
Pins states undefined
Turn on power while RESETP is low in advance
Vcc, Vcc_PLL1, Vcc_PLL2, Vcc_RTC: 1.5 V power
Vcc, Vcc_PLL1, Vcc_PLL2, Vcc_RTC (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
Note:
Handling of CA pin
The CA pin must be ensured to go high before power is turned on. When it is not ensured,
through current flows to the I/O buffer, etc. and it may cause the LSI damage even if a
clock is not input.
Rev. 3.00 Jan. 18, 2008 Page 1306 of 1458
REJ09B0033-0300