Comtech EF Data SNM-1010L - Manual (Page 167)

SNM-1010L Data/Control Modem Revision 0
Theory of Operation MN/SNM1010L.OM
6.2 Monitor and Control
The modem uses a sophisticated microcontroller module to perform M&C functions. This
module is located on the demodulator board. The M&C monitors the modem and
provides configuration updates to other modules within the modem as required.
The modem configuration parameters are maintained in battery-backed RAM. The RAM
provides for total recovery after a power-down situation.
Notes:
1. Extensive fault monitoring and status gathering are provided.
2. Modem functions are accessible through a user port interface.
6.2.1 Non-Volatile Memory
Non-volatile memory on the M&C module allows it to retain configuration information
without prime power for at least one year. Should the modem be powered down, the
following sequence is carried out when power is reapplied to the M&C:
1. The microcontroller checks the non-volatile memory RAM to see if data has been
retained. If data has been retained, the modem is reconfigured to that information.
2. If non-volatile memory fails the data test, a default configuration from ROM is
loaded into the system.
6.2.2 User Port
Modem functions can be remotely controlled and monitored via the User port on the back
panel. Refer to Chapter 4.
6.2.3 M&C Theory of Operation
The M&C module is built around the Intel 80C32 microcontroller, operating at 11.0592
MHz. The microsystem is designed to support up to 512 kilobytes (Kb) of read-only code
memory, and up to 32 Kb of non-volatile, random-access data memory.
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