GDK-100
DIGITAL KEY TELEPHONE SYSTEM
17
2.4.6 MPB (Main Processor Board)
The MPB controls and manages the communication between peripheral interface, supervises all
resources in the system, controls the gain adjustment of PCM signal, generates system tone and
manages call processing of the system.
The MPB, incorporates the system's RAM, master clock, MOH 1 port, RS-232C 1 port and watchdog
circuitry as well as the system's PCM voice processing and main micro-processor. The micro-processor is
a 16 bit high speed CPU which receives and transmits signaling information from/to other PCBs, controls
feature activation, and PCM time-slot interchange. The MPB contains 512 Kbytes of RAM and can be
expanded to 1Megabyte with the MEMU or SMEMU. RAM associated with the system database and the
real-time-clock are protected from power loss by a long life high energy lithium battery. On board ROM
contains PCM tone, gain table etc. needed for the digital voice processing.
The 2 Megabytes of ROM on MPB contains basic system operating software.
MPB should be installed in the MPB slot in the right most side of BKSU/SBKSU.
MPB contains 1 internal MOH source, 1 RS-232C.
Add-on boards: MEMU, SMEMU, PLLU, MODU
2.4.7 MISB (Miscellaneous Board)
The MISB incorporates the circuitry and interfaces for common optional features including:
•
External Paging
2 ports
•
External Control Contacts
4 contacts
•
External BGM & MOH
2 ports
•
Alarm/Door Detection
1 input
•
RS-232C(optional SIU)
2 ports
A RJ21 type female connector is mounted on the front edge of the MISB for the connection to above
circuits except RS232C serial interfaces.
One MSIB board can be installed only in the slot No. 8.
Add-on board: SIU