Memory Organization - 256K Byte Ram Board - HP 9030 Service Manual

Theory of Operation
2-13
Memory Organization - 256K Byte RAM Board
Up to 10 RAM boards can be configured in a processor stack. Each board has a Memory Controller
(MC) and 256K, 512K, or 1 Megabyte of RAM. This section will cover the theory of operation of
the 256K board (Figure 2-5), and following sections will cover the other RAM boards.
,
.-
t
I~
16K X 8
RAM
•
I~
16K X 8
RAM
.-
•
0-+
16K X 8
RAM
-
t
4...-..
16K X 8
RAM
I
CHIP SELECTS
I
,8
MEMORY ADDRESS BUS
,8
,
I
.-
•
~ --+-
16K X 8 f+-I~
r+
RAM
-
•
f+-I
4~
16K X 8
f+-I~ I~
RAM
•
f+-I-
~
16K X 8
f+-I
1...-..
RAM
-
•
+--
~
16K X 8
f+-
...-..
RAM
TO
MPB
j
32
I
MEMORY
CONTROLLER
t t
t t
t
,8
~EMr
O:Tj
B~S
I
-
.-
16K
x
8
+1~
r+
RAM
-
•
16K X 8
+1~
~
RAM
-
l
16K X 8
~. 1"'-"
RAM
-
•
16K X 8
+-- 4"'-"
RAM
/8
I
t
16K
x
8
RAM
.-
t
16K X 8
RAM
.-
t
16K X 8
RAM
.-
t
16K X 8
RAM
Figure 2-5. 256K RAM Finstate Block Diagram
,7
I
+
~ r+
16K
x
8
f+-I
RAM
+
f+-4
~
16K X 8
f+-4
RAM
+
f+-4~
~
16K X 8
f+-4-
RAM
+
+-- 4"'-"
16K X 8
+-
RAM