AT&T 3B2/300 Technical Reference Manual page 392

- - - - - - - - - - - - - - - - - - - - - - - - - - FUNCTIONAL DESCRIPTION
RANDOM ACCESS MEMORY CARDS
/
CM191A/B/C/D and CM192B Memory Cards
Functional block diagrams of the various Version 2 Random Access Memory (RAM) cards are
provided in Figures 3-39 through 3-43. Functionally, all memory cards consist of address drivers,
control drivers, and a Dynamic Random Access Memory (DRAM) circuit. The various types and sizes
of cards are identified to the system during self-configuration by the state of the S1ZE64K[O] and
ONEBANK[O] signals. The various types of memory cards in relation to the state of the S1ZE64K[O] and
ONEBANK[O] signals are summarized in the following table.
CARD TYPE SIZE64K[O) ONEBANK[O)
CM191A
(0.25 M)
0
=
64K 0
=
1 BANK
CM191B
(1.0 M)
1
=
256K 0
=
1 BANK
CM191C
(1.0 M)
1
=
256K 0
=
1 BANK
CM191D
(2.0 M)
1
=
256K 1
=
2 BANKS
CM192B
(2.0 M)
1
=
256K 1
=
2 BANKS
FUNCTIONAL DESCRIPTION 3-139