Motorola MPC533 Reference Manual page 1107

K.8 Power-Up/Down Sequencing
The supply symbols used in this section are described in Table K-9.
.
Symbol
V
DDH
(High Voltage
Supply Group)
V
DDL
(Low Voltage
Supply Pins)
V
DDKA
(Low Voltage
Keep-Alive
Supply Pins
1
Any supply in the V
which it supplies is not required during "Keep-alive."
There are two power-up/down options. Choosing which one is required for an application
will depend upon circuitry connected to 2.6-V compliant pins and dual 2.6-V/5-V
compliant pins. Power-up/down option A is required if 2.6-V compliant pins and dual
2.6-V/5-V compliant pins are connected to the 5-V supply with a pull-up resistor or driven
by 5-V logic during power-up/down. In applications for which this scenario is not true the
power-up/down option B may be implemented. Option B is less stringent and easier to
ensure over a variety of applications.
Refer to Table 2-1 for a list of 2.6 V and dual 2.6V/5 V compliant pins.
The power consumption during power-up/down sequencing will stay below the operating
power consumption specifications when following these guidelines.
The V
V
DDL
K.8.1 Power-Up/Down Option A
The Option A power-up sequence (excluding V
1. V ≤ V
DDH DDL
2. V V
≥
DDH DDL
MOTOROLA
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Table K-9. Power Supply Pin Groups
Supply to the 5-V pads for output driver (V
Supply to the analog (QADC64E) circuitry (V
High voltage supply to the flash module (V
Supply to low voltage pad drivers (QVDDL, NVDDL)
Supply to all low voltage internal logic (V
Supply to low voltage flash circuitry (V
Supply to system PLL
Supply to oscillator and other circuitry for keep-alive functions
(KAPWR).
1
group can be powered with the V
DDKA
ramp voltage should be kept below 50V/mS and the
DDH
ramp rate less that 25V/mS.
+ 3.1 V (V cannot lead V
DDH
- 0.5 V (V cannot lag V
DDH
Appendix K. Electrical Characteristics
Types of Power Pins
)
DDH
DDA
FLASH
)
DD
)
DDF
if the function
DDL
NOTE:
) is
DDKA
by more than 3.1 V)
DDL
by more than 0.5 V)
DDL
Power-Up/Down Sequencing
)
)
K-13