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EM Units
If the DM Area capacity of 24K words is insufficient, an EM Unit (sold separately)
can be added to create an EM (Expansion Data Memory) Area providing up to
256K words of additional memory. In a duplex system, the left and right CPU
Units must have EM Units with the same specifications.
There are three models of EM Units available, as shown in the following table.
Model
Memory capacity
Memory banks
CV1000-DM641
64K words
2 (0 and 1)
CV1000-DM151
128K words
4 (0 to 3)
CV1000-DM251
256K words
8 (0 to 7)
The following diagram shows the structure of the EM Unit and identifies its main
components.
Memory chip
Pullout
lever
Backup
capacitor
EM Unit
CPU
connector
The EM Area operates the same as the DM Area, but the EM Area memory is
contained in the EM Unit, while DM Area memory is internal.
EM Area memory is divided into banks of 32K words each. Words E00000 to
E32765 of the current bank can be accessed. The current bank number is con-
tained in the least significant digit of A511. A511 is in a read-only area, but the
current bank number can be changed with the EMBC(171) instruction. Refer to
Section 5 Instruction Set for details.
Refer to the CVM1D Installation Guide for details on installing and removing EM
Units.
EM Units
Section 2-3
Summary of Contents for CVM1D
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