Intel 386 - Manual (Page 157)

Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
6-44
6.6.5 Non-Paged DRAM Interface
This interface is similar to the Paged DRAM Interface, except that in this case, the lower address
bits are routed to the Row Address Buffer and the higher address bits to the Column Address
Buffer. This is done to simplify the RAS#-Only Refresh logic. The PLD in this case enables the
Row Address Buffer and asserts the RAS# signal (shaded sections in the figure) during a Refresh
Cycle. Refer to Chapter 15, “REFRESH CONTROL UNIT,” for more information.
A single multiplexer can be used instead of the separate row and column address buffers.
Figure 6-19. Intel386 EX Processor and Non-Paged DRAM Interface
Intel386™ EX
Embedded Processor
Row
Address
Buffer
PLD
Lower Address
Row
Address
Non-paged
DRAM
Column
Address
Address
Upper Address
OE_ROW#
OE_COL#
RAS#
CAS#
BHE#
BLE#
A3265-02
Column
Address
Buffer
CS n#
REFRESH#
Note:
A single mux can be used in place of the row and column address buffers.