Specifications

AC65/AC75 Hardware Interface Description
3.12 USB Interface
s
AC65_AC75_HD_v01.002 Page 53 of 117 2006-10-30
Confidential / Released
3.12 USB Interface
AC65/AC75 supports a USB 2.0 Full Speed (12Mbit/s) device interface. It can be operated on a USB 2.0 Full
Speed or High Speed root hub (a PC host), but not on a generic USB 2.0 High Speed hub which translates High
Speed (480 Mbit/s/) to Full Speed (12 Mbit/s).
The USB port has different functions depending on whether or not Java is running. Under Java, the lines may be
used for debugging purposes (see [16] for further detail). If Java is not used, the USB interface is available as a
command and data interface and for downloading firmware.
The USB I/O-pins are capable of driving the signal at min 3.0V. They are 5V I/O compliant.
To properly connect the module’s USB interface to the host a USB 2.0 compatible connector is required. Fur-
thermore, the USB modem driver delivered with AC65/AC75 must be installed as described below.
The USB host is responsible for supplying, across the VUSB_IN line, power to the module’s USB interface, but
not to other AC65/AC75 interfaces. This is because AC65/AC75 is designed as a self-powered device compliant
with the “Universal Serial Bus Specification Revision 2.0”
2
.
Figure 18: USB circuit
To properly connect the module's USB interface to the host a USB 2.0 compatible connector is required. For
more information on how to install a USB modem driver and on how to integrate USB into AC65/AC75 applica-
tions see [11].
Table 14: DCE-DTE wiring of ASC1
V.24 circuit DCE DTE
Pin function Signal direction Pin function Signal direction
103 TXD1 Input TXD Output
104 RXD1 Output RXD Input
105 RTS1 Input RTS Output
106 CTS1 Output CTS Input
2.
The specification is ready for download on http://www.usb.org/developers/docs/