ZEUS Technical Manual | Power and power management |
|
|
CompactFlash power management
The power supply to the CompactFlash interface is controlled via software, and supports hot swap card insertion and CompactFlash power down states. GPIO97 on the PXA270 (signal CF_PWEN) is used to control the power supply switch. Setting this line to logic ‘0’ switches off the power to the CompactFlash interface. The current- limiting (1A) and thermal protection features of the power switch eliminate the need for the fuse. The power supply to the CompactFlash is derived from 3.3V supply.
CPU_ GPIO97 (CF_PWEN) | CF power |
0 | Power off |
1 | Power on |
|
|
Wireless modem power management
The power supply to the wireless modem interface (VCC_MODEM) is controlled by SYS_EN signal of the PXA270, and is switched off when PXA270 is in
GSM_ON and GPS_ON control signals are provided on the ZEUS Modem connector (J23). They are controlled by
USB power management
A USB power control switch controls the power, and protects against
If the USB voltage VBUSx is
The following table shows the PXA270 assignments for power enable and
Host 1/2 functions PXA270 GPIO | Active |
USB_PWE1 GPIO89 High
USB_OC1# GPIO88 Low
USB_PWE2 GPIO22 High
USB_OC2# GPIO114 Low
© 2007 Eurotech Ltd Issue D | 70 |