Gemalto M2M GmbH PXS8 Manuel D’Utilisation
PXS8 Hardware Interface Description
3.3 USB Interface
29
PXS8_HD_v03.000
Page 23 of 41
2012-11-30
Confidential / Preliminary
3.3
USB Interface
PXS8 supports a USB 2.0 High Speed (480Mbit/s) device interface that is Full Speed (12Mbit/s)
compliant. The USB interface is primarily intended for use as command and data interface and
for downloading firmware.
compliant. The USB interface is primarily intended for use as command and data interface and
for downloading firmware.
The external application is responsible for supplying the VUSB_IN line. This line is used for ca-
ble detection only. The USB part (driver and transceiver) is supplied by means of BATT+. This
is because PXS8 is designed as a self-powered device compliant with the “Universal Serial Bus
Specification Revision 2.0”
ble detection only. The USB part (driver and transceiver) is supplied by means of BATT+. This
is because PXS8 is designed as a self-powered device compliant with the “Universal Serial Bus
Specification Revision 2.0”
1
.
Figure 3: USB circuit
To properly connect the module's USB interface to the external application, a USB 2.0 compat-
ible connector and cable or hardware design is required.
ible connector and cable or hardware design is required.
1.
The specification is ready for download on
VBUS
DP
DN
VREG (3V075)
BATT+
USB_DP
2)
lin. reg.
GND
Module
Detection only
VUSB_IN
USB part
1)
RING0
Host wakeup
1)
All serial (including R
S
) and pull-up resistors for data lines are implemented.
USB_DN
2)
2)
If the USB interface is operated in High Speed mode (480MHz), it is recommended to take
special care routing the data lines USB_DP and USB_DN. Application layout should in this
case implement a differential impedance of 90Ohm for proper signal integrity.
case implement a differential impedance of 90Ohm for proper signal integrity.
WAKEUP
R
S
R
S
SMT