User's Manual
Table Of Contents
- Document history
- Introduction
- Product concept
- Application Interface
- Antenna interface
- Electrical, reliability and radio characteristics
- Mechanics
- Reference Approval
- Design example
- List of parts and accessories

MC55/56 Hardware Interface Description
Confidential / Preliminary
s
MC55/56_hd_v03.00 Page 24 of 104 16.08.2005
Mode Function
Charge-only mode Limited operation for battery powered applications. Enables charging while
module is detached from GSM network. Limited number of AT commands is
accessible. There are several ways to launch Charge-only mode:
• From POWER DOWN mode: Connect charger to the charger input pin of the
external charging circuit and the module’s POWER pin when MC55/56 was
powered down by AT^SMSO.
• From Normal mode: Connect charger to the charger input pin of the external
charging circuit and the module’s POWER pin, then enter AT^SMSO.
Charge mode
during normal
operation
Normal operation (SLEEP, IDLE, TALK, GPRS IDLE, GPRS DATA) and
charging running in parallel. Charge mode changes to Charge-only mode when
the module is powered down before charging has been completed.
See Table 11 and Table 12 for the various options of waking up MC55/56 and proceeding from one
mode to another.