Specifications

XT65/XT75 Hardware Interface Description
3.17 Control Signals
s
XT65_XT75_HD_v01.001 Page 71 of 133 2007-1-8
Confidential / Released
3.17.2 Using the SYNC Pin to Control a Status LED
As an alternative to generating the synchronization signal, the SYNC pin can be configured to drive a status LED
that indicates different operating modes of the XT65/XT75 module. To take advantage of this function the LED
mode must be activated with the AT^SSYNC command and the LED must be connected to the host application.
The connected LED can be operated in two different display modes (AT^SSYNC=1 or AT^SSYNC=2). For
details please refer to [1].
Figure 35: LED Circuit (Example)
Especially in the development and test phase of an application, system integrators are advised to use the LED
mode of the SYNC pin in order to evaluate their product design and identify the source of errors.
To operate the LED a buffer, e.g. a transistor or gate, must be included in your application. A sample circuit is
shown in Figure 35. Power consumption in the LED mode is the same as for the synchronization signal mode.
For details see Table 29, SYNC pin.