Controls And Indicators Interface; Reset; Vref Reference Regulator - Motorola G24 Developer's Manual

Controls and Indicators Interface

Controls and Indicators Interface
The G24 incorporates several interface signals for controlling and monitoring the module's
operation. The following paragraphs describes these signals and their operation.
Table 2-20

Reset

The RESET_N output signal indicates the G24's operating status. This signal is set high after
power up, when G24 is operating. It is set low when G24 is powered off.
When the RESET_N signal is low, the G24 application interface signals are disabled and do not
represent any valid data or state. Furthermore, the application input signals connected to the G24
interface must be disabled and set low when RESET_N is low.

VREF Reference Regulator

The G24 incorporates a regulated voltage output, VREF. The regulator provides a 2.75V output
for use by the customer application. This regulator can source up to 200 mA of current to power
any external digital circuits.
Important:
44
gives a description of the controls and indicators signals.
Table 2-20: Controls and Indicators
Connector Pin Signal Name
25 RESET_N
27 VREF
26 WKUPO_N
41 ANT_DET
49 GPRS/GSM
39 TXEN_N
28, 30, 32, 34, 36, GPIO 1-8
38, 40, 42
The VREF regulator is powered from the G24's main power supply, and therefore
any current sourced through this regulator originates from the G24 VCC supply.
The overall VCC current consumed by G24 is directly affected by the VREF
operation. The G24 current consumption rises with respect to the current sourced
through VREF.
Module Hardware Description
Description
G24 system reset output indicator.
When high, G24 is operating.
2.75V regulated output.
Supplies external circuits up to
200mA.
Host application wake-up signal indi-
cator.
Antenna physical connection detect
indicator.
Network status indicator.
Transmission burst indication.
General purpose IO signals for cus-
tomer use.
January 1, 2006