Order this document
by MCM67M618B/D
SEMICONDUCTOR TECHNICAL DATA
MCM67M618B
Advance Information
64K x 18 Bit BurstRAM
Synchronous Fast Static RAM
With Burst Counter and Self–Timed Write
The MCM67M618B is a 1,179,648 bit synchronous static random access
memory designed to provide a burstable, high–performance, secondary cache
for the MC68040 and PowerPC microprocessors. It is organized as 65,536
words of 18 bits, fabricated using Motorola’s high–performance silicon–gate
BiCMOS technology. The device integrates input registers, a 2–bit counter, high
speed SRAM, and high drive capability outputs onto a single monolithic circuit
for reduced parts count implementation of cache data RAM applications. Syn-
chronous design allows precise cycle control with the use of an external clock
(K). BiCMOS circuitry reduces the overall power consumption of the integrated
functions for greater reliability.
FN PACKAGE
PLASTIC
CASE 778–02
PIN ASSIGNMENT
7
6
5
4
3
2
1 52 51 50 49 48 47
46 DQ8
Addresses (A0 – A15), data inputs (DQ0 – DQ17), and all control sig-
nals, except output enable (G), are clock (K) controlled through posi-
tive–edge–triggered noninverting registers.
DQ9
8
9
DQ10
V
45 DQ7
44 DQ6
10
11
12
CC
SS
V
43
42
V
V
Bursts can be initiated with either transfer start processor (TSP) or
transfer start cache controller (TSC) input pins. Subsequent burst
addresses are generated internally by the MCM67M618B (burst
sequence imitates that of the MC68040) and controlled by the burst
address advance (BAA) input pin. The following pages provide more
detailed information on burst controls.
Write cycles are internally self–timed and are initiated by the rising
edge of the clock (K) input. This feature eliminates complex off–chip
write pulse generation and provides increased flexibility for incoming
signals.
CC
SS
DQ11
DQ12
DQ13
DQ14
13
14
15
41 DQ5
40 DQ4
39 DQ3
V
V
DQ15
DQ16
DQ17
16
17
18
19
20
38 DQ2
SS
CC
37
36
V
V
SS
CC
35 DQ1
34 DQ0
21 22 23 24 25 26 27 28 29 30 31 32 33
Dual write enables (LW and UW) are provided to allow individually
writeable bytes. LW controls DQ0 – DQ8 (the lower bits), while UW
controls DQ9 – DQ17 (the upper bits).
This device is ideally suited for systems that require wide data bus
widths and cache memory.
PIN NAMES
A0 – A15 . . . . . . . . . . . . . . . . Address Inputs
K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clock
BAA . . . . . . . . . . . . Burst Address Advance
LW . . . . . . . . . . . . Lower Byte Write Enable
UW . . . . . . . . . . . . Upper Byte Write Enable
TSP, TSC . . . . . . . . . . . . . . . . Transfer Start
E . . . . . . . . . . . . . . . . . . . . . . . . . Chip Enable
G . . . . . . . . . . . . . . . . . . . . . . Output Enable
DQ0 – DQ17 . . . . . . . . . . Data Input/Output
•
•
•
•
•
•
•
•
•
•
Single 5 V ± 5% Power Supply
Fast Access Times: 9/10/12 ns Max
Byte Writeable via Dual Write Strobes
Internal Input Registers (Address, Data, Control)
Internally Self–Timed Write Cycle
TSP, TSC, and BAA Burst Control Pins
Asynchronous Output Enable Controlled Three–State Outputs
Common Data Inputs and Data Outputs
High Board Density 52–PLCC Package
3.3 V I/O Compatible
V
CC
V
SS
. . . . . . . . . . . . . . . . + 5 V Power Supply
. . . . . . . . . . . . . . . . . . . . . . . . . . Ground
All power supply and ground pins must be con-
nected for proper operation of the device.
The PowerPC name is a trademark of IBM Corp., used under license therefrom.
This document contains information on a new product under development. Motorola reserves the right to change or discontinue this product without notice.
REV 1
7/15/97
Motorola, Inc. 1997
MOTOROLA FAST SRAM
MCM67M618B
1