User guide

UC864-E/G/WD/WDU Hardware User Guide

1vv0300766a Rev.4

- 03/02/09

During the Initialization state, any kind of AT-command is not available. DTE must be

waiting for the Activation state to communicate with UC864-E/G/WD/WDU.

NOTE:

To check if the UC864-E/G/WD/WDU has powered on, the hardware line PWRMON

must be monitored. When PWRMON goes high, the module has powered on.

NOTE:

Do not use any pull up resistor on the ON# line, it is internally pulled up. Using pull up

resistor may bring to latch up problems on the UC864-E/G/WD/WDU power regulator

and improper power on/off of the module. The line ON# must be connected only in

open collector configuration.

NOTE:

In this document all the lines are inverted. Active low signals are labeled with a name

that ends with a "#" or with a bar over the name.

NOTE:

UC864-E/G/WD/WDU turns fully on also by supplying power to the Charge pad

(provided there is a battery on the VBATT pads).

NOTE:

UC864-E version also turns fully on by supplying power to the USB_VBUS pin

(provided there is a battery on the VBATT pads). Care must be taken to avoid

supplying power to the USB_VBUS pin before the module turns on. To check if the

UC864-E has powered on, the hardware line PWRMON must be monitored. When

PWRMON goes high, the module has powered on.