PDM34078
3.3V 32K x 32 Fast CMOS
Synchronous Static RAM
with Burst Counter
1
2
and Output Register
Description
Features
The PDM34078 is a 1,048,576 bit synchronous
random access memory organized as 32,768 x 32
bits. This device designed with burst mode
capability and interface controls to provide high-
performance in second level cache designs for x86,
Pentium, 680x0, and PowerPC microprocessors.
Addresses, write data and all control signals except
output enable are controlled through positive edge-
triggered registers. Write cycles are self-timed and
are also initiated by the rising edge of the clock.
Controls are provided to allow burst reads and
writes of up to four words in length. A 2-bit burst
address counter controls the two least-significant
bits of the address during burst reads and writes.
The burst address counter selectively uses the 2-bit
counting scheme required by the x86 and Pentium
or 680x0 and PowerPC microprocessors as con-
trolled by the mode pin. Individual write strobes
provide byte write for the four 8-bit bytes of data.
An asynchronous output enable simplifies interface
to high-speed buses.
■ Interfaces directly with the x86, Pentium™, 680X0
and PowerPC™ processors
(100, 80, 66, 60, 50 MHz)
■ Single 3.3V power supply
■ Mode selectable for interleaved or linear burst:
Interleaved for x86 and Pentium
Linear for 680x0 and PowerPC
■ High-speed clock cycle times:
10, 12.5, 15, 16.7 and 20 ns
■ High-density 32K x 32 architecture with burst
address counter and output register
■ Fully registered inputs and outputs for pipelined
operation
3
4
5
■ High-output drive: 30 pF at rated T
A
■ Asynchronous output enable
■ Self-timed write cycle
■ Separate byte write enables and one global write
enable
■ Internal burst read/write address counter
■ Internal registers for address, data, controls
■ Output data register
6
7
■ Burst mode selectable
■ Sleep mode
■ Packages:
8
100-pin QFP - (Q)
100-pin TQFP - (TQ)
9
10
11
12
TM
i486, Pentium are trademarks of Intel Corp. PowerPC is a trademark of the International Business Machines Corporation.
Rev 1.0 - 5/01/98
1