Product Specs

Packet Modem Spec Rev6.doc 33 06/09/00
6.3.5.1 DM Port Functionality:
Allows OEM VAR to perform debugging and field SW upgrades / data collection
using DM tool or PST (available from Qualcomm separately)
Uses TTL levels, un-translated
TXD, RXD, RTS, CTS, DTR, POWER, PROGRAM, GND
TXD, RXD, RTS and CTS for hardware flow control
DTR to turn on the module from DM
POWER for an active translator DM cable
PROGRAM is used to unlock the boot block with >13V applied
Flash unlock through a 2 pin jumper header on the board
6.4 Grounding
In order to keep the “clean” and “dirty” grounds isolated, the chassis ground
of the interface connector as well as that of the DM connector will be isolated
from the ground return of the module.
The chassis ground is the ground that is connected to the DB 25 User
Interface and DM connector shields. The module ground is the same as the
serial port ground return. Depending on the application, these may be
independent or connected together.
Both the chassis grounds of the DM and Interface connector are taken to
mounting holes where the solder mask is exposed on both sides of the board
in order that the mounting hole may serve as a chassis ground. The two
mounting holes will provide for independent grounding of the two connectors.
It is left to the user to ground the two connectors per the application.
Provision is made, on the board using a DNI resistor, that allows the user to
connect the two grounds as well as the module ground easily in case the
application does require the interconnection of the two grounds.
The power and signal ground for the other signals / power is on a few pins of
the DB 25 User Interface connector as well as the DM connector.
The RF connector ground is the same as the signal and power ground. The
user should be aware of this fact so that ground loops can be avoided in the
final installation.