AT&T 3B2/300 Technical Reference Manual page 327

FUNCTIONAL D E S C R I P T I O N - - - - - - - - - - - - - - - - - - - - - - - - - -
TO/FROM
CPU
FROM
CPU
AND
I/0 BUS
TO/FROM
I/0 BUS
TO/FROM
CPU
TO
I/0
BUS
(
[
"
'
[:
(
DUAL PORT DYNAMIC RANDOM ACCESS MEMORY CONTROLLER
PPAI0-02[1]
I
ADDRESS GENERATION LOGIC
MUXA9-0[1]
I (ADDRESS MULTIPLEXER)
DIOMST[O]
ROW[l ]COL[O]
I
REFRESH
I
ENCAMUX[O]
LOGIC
PRIORITIZED
I
ACCESS CONTROL
ARBITRATION
I
REQUESTS
-
SEQUENCER
SIGNALS
LOGIC
I
-
REFRESH (REFREQ[l])
CONTROL
I/0-DRAM (LPBRQ[!])
'
SIGNALS
CPU-DRAM (CPUMEMRQ[l])
CPU-I/0 (CPUIORQ[l])
'
ACCESS
REQUESTS
I
I
REQUEST
CONTROL
I
GENERATOR
SIGNALS
PP A23-00[l]
BYPASS LOGIC
CONTROL
SIGNALS
PDIS-00[1]
BYTE
MD(31-00[l]
ROTATE
-
DATA
-
UNIT
MULTIPLEXER
CIRCUIT
D31-00[l]
-
FAULT (FLT(O])
PARITY
4 - -
GENERATION
WE[O]
MEMORY PARITY ERROR (MPARER(O])
AND
PERIPHERAL FAULT (PFLT(O])
CHECK
MPAR3-0[1]
CIRCUITS
'
-
-
-
-
-
. .
TO/FROM
RAM
CARDS
Figure 3-24: Dual Port Dynamic Random Access Memory Controller - Functional Block Diagram
3-74 TECHNICAL REFERENCE MANUAL