Eurotech Appliances ZEUS PXA270 - Manual (Page 67)

ZEUS Technical Manual Power and power management
© 2007 Eurotech Ltd Issue D 67
Frequency
System bus
frequency
Active power
consumption
typ. Idle power
consumption
typ.
Conditions
VCC_SRAM = 1.1V; VCC_PLL = 1.3V;
VCC_MEM, VCC_BB,
VCC_USIM, VCC_LCD = 1.8V;
VCC_IO, VCC_BATT,VCC_USB=3.0V
520MHz 208MHz 747 mW 222 mW VCC_CORE = 1.45V
416MHz 208MHz 570 mW 186 mW VCC_CORE = 1.35V
312MHz 208MHz 390 mW 154 mW VCC_CORE = 1.25V
312MHz 104MHz 375 mW 109 mW VCC_CORE = 1.1V
208MHz 208MHz 279 mW 129 mW VCC_CORE = 1.15V
104MHz 104MHz 116 mW 64 mW VCC_CORE = 0.9V
13MHz CCCR[CPDIS]=1 44.2 mW - VCC_CORE = 0.85V
PXA270 low power modes
Power consumption
typ. Conditions
VCC_MEM, VCC_BB, VCC_USIM, VCC_LCD = 1.8V
VCC_IO, VCC_BATT, VCC_USB= 3.0V
13MHz idle mode (LCD on) 15.4mW VCC_CORE, VCC_SRAM, VCC_PLL = 0.85V
13MHz idle mode (LCD off) 8.5mW VCC_CORE, VCC_SRAM, VCC_PLL = 0.85V
Deep sleep mode 0.1mW VCC_CORE, VCC_SRAM, VCC_PLL = 0V
Sleep mode 0.16mW VCC_CORE, VCC_SRAM, VCC_PLL = 0V
Standby mode 1.7mW VCC_CORE, VCC_SRAM, VCC_PLL = 3.0V
Wake-up sources
The PXA270 offers two sleep modes:
•
Sleep mode
offers lower power consumption by switching off most internal units.
There is no activity inside the processor, except for the units programmed to retain
their state in the PSLR register, the real time clock and the clocks and power
manager. Because internal activity has stopped, recovery from sleep mode must
occur through an external or internal real time clock event. External wake-up
sources are GPIO edge detects (they are listed in the section PXA270 GPIO
pin assignments , page 22 ).
•
Deep-sleep mode
offers the lowest power consumption by powering most units off.
There is no activity inside the processor, except for the real time clock (RTC) and
the clocks and power manager. Because internal activity has stopped, recovery
from deep-sleep mode must be through an external event or an RTC event. In
deep-sleep mode, all the PXA270 power supplies (VCC_CORE, VCC_SRAM,
VCC_PLL, VCC_IO excluding VCC_BATT) are powered off for minimized power
consumption. On the ZEUS, the main +3.3V rail supplies the VCC_IO power domain
of the PXA270. Since the +3.3V supply is switched off in deep-sleep mode, all the on-
board peripherals are powered off and it is not possible to use external wake-up
sources. In this situation, recovery from deep-sleep mode must be through an
internal RTC event.
For more information on PXA270 power management, see section 3.6 in the Intel
PXA27x Processor Family Developer’s Manual
, included on the Development Kit CD.