Motorola MCM67C618BFN5, MCM67C618BFN7 Datasheet

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

Product Preview

64K x 18 Bit BurstRAM
Synchronous Fast Static RAM

With Burst Counter and Registered Outputs

The MCM67C618B is a 1,179,648 bit synchronous static random access
memory designed to provide a burstable, high–performance, secondary cache
for the i486 and Pentium microprocessors. It is organized as 65,536 words
of 18 bits, fabricated with Motorola’s high–performance silicon–gate BiCMOS
technology. The device integrates input registers, a 2–bit counter, high speed
SRAM, and high drive registered output drivers onto a single monolithic circuit
for reduced parts count implementation of cache data RAM applications. Syn­chronous 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 .

Addresses (A0 – A15), data inputs (D0 – D17), and all control signals except
output enable (G
inverting registers.

This device contains output registers for pipeline operations. At the rising edge
of K, the RAM provides the output data from the previous cycle.

Output enable (G

Burst can be initiated with either address status processor (ADSP) or address
status cache controller (ADSC
generated internally by the MCM67C618B (burst sequence imitates that of the
i486 and Pentium) and controlled by the burst address advance (ADV
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.

Dual write enables (LW
bytes. L W
(the upper bits).

This device is ideally suited for systems that require wide data bus widths and
cache memory . See Figure 2 for applications information.

• Single 5 V

• Fast Access Time/Fast Cycle Time = 5 ns/100 MHz, 7 ns/80 MHz

• Byte Writeable via Dual Write Enables

• Internal Input Registers (Address, Data, Control)

• Output Registers for Pipelined Applications

• Internally Self–Timed Write Cycle

• ADSP

, ADSC, and ADV Burst Control Pins

• Asynchronous Output Enable Controlled Three–State Outputs

• Common Data Inputs and Data Outputs

• 3.3 V I/O Compatible

• High Board Density 52–Lead PLCC Package

) are clock (K) controlled through positive–edge–triggered non-

) is asynchronous for maximum system design flexibility.

) input pins. Subsequent burst addresses can be

) input pin.

and UW) are provided to allow individually writeable

controls DQ0 – DQ8 (the lower bits), while UW controls DQ9 – DQ17

± 5% Power Supply

DQ10

DQ11
DQ12
DQ13

DQ14

DQ15
DQ16
DQ17

MCM67C618B

FN PACKAGE

PLASTIC

CASE 778–02

PIN NAMES

A0 – A15 Address Inputs. . . . . . . . . . . . . . . .

K Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ADV
LW
UW
ADSC
ADSP
E
G

DQ0 – DQ17 Data Input/Output. . . . . . . . . .

V

CC

V

SS

NC No Connection. . . . . . . . . . . . . . . . . . . . .

All power supply and ground pins must be
connected for proper operation of the device.

PIN ASSIGNMENT

A6A7E

7 6 5 4 3 2 1525150494847

8

DQ9

9

V

10

CC

V

11

SS

12
13
14

15

V

16

SS

V

17

CC

18
19
20

21 22 23 24 25 26 2728 29 30 31 32 33

A4A3A2

A5

UW

LW

A1

ADSC

A0

Order this document

by MCM67C618B/D

Burst Address Advance. . . . . . . . . . . .

Lower Byte Write Enable. . . . . . . . . . . .

Upper Byte Write Enable. . . . . . . . . . . .

Controller Address Status. . . . . . . . .

Processor Address Status. . . . . . . . .

ADSP

ADV

SS

CC

V

V

+ 5 V Power Supply. . . . . . . . . . . . . . . .

K

A15

Chip Enable. . . . . . . . . . . . . . . . . . . . . . . . .

Output Enable. . . . . . . . . . . . . . . . . . . . . .

G

A8A9A10

A13

A14

A12

46
45

44
43
42
41
40
39
38
37
36
35
34

Ground. . . . . . . . . . . . . . . . . . . . . . . . . .

DQ8
DQ7
DQ6
V

CC

V

SS

DQ5
DQ4

DQ3
DQ2
V

SS

V

CC

DQ1
DQ0

A11

BurstRAM is a trademark of Motorola, Inc.
i486 and Pentium are trademarks of Intel Corp.

This document contains information on a product under development. Motorola reserves the right to change or discontinue this product without notice.

7/96

 Motorola, Inc. 1996

MOTOROLA FAST SRAM

MCM67C618B

1

BLOCK DIAGRAM (See Note)

K

ADSC
ADSP

A0 – A15

UW

LW

E

G

DQ0 – DQ8

DQ9 – DQ17

ADV

CLR

ADDRESS

REGISTER

WRITE

REGISTER

ENABLE

REGISTER

9
9

BURST LOGIC

Q0

BINARY

COUNTER

Q1

A1 – A0

16

A0

A1

2

A2 – A15

A0

′

INTERNAL
ADDRESS

16

18

DATA–IN

REGISTERS

9 9

64K x 18

MEMORY

ARRAY

9

9

DATA–OUT

REGISTERS

OUTPUT
BUFFER

NOTE: All registers are positive–edge triggered. The ADSC or ADSP signals control the duration of the burst and the start of the

next burst. When ADSP

is sampled low, any ongoing burst is interrupted and a read (independent of W and ADSC) is per-

formed using the new external address. Alternatively , an ADSP–initiated two cycle WRITE can be performed by asserting

and a valid address on the first cycle, then negating both ADSP and ADSC and asserting LW and/or UW with valid

ADSP
data on the second cycle (see Single Write cycle in WRITE CYCLES timing diagram).
When ADSC
on W

is sampled low (and ADSP is sampled high), any ongoing burst is interrupted and a read or write (dependent

) is performed using the new external address. Chip enable (E) is sampled only when a new base address is loaded.
After the first cycle of the burst, ADV controls subsequent burst cycles. When ADV is sampled low, the internal address is
advanced prior to the operation. When ADV

is sampled high, the internal address is not advanced, thus inserting a wait state

into the burst sequence accesses. Upon completion of a burst, the address will wrap around to its initial state. See BURST

SEQUENCE TABLE. W rite refers to either or both byte write enables (LW

BURST SEQUENCE TABLE

External Address A15 – A2
1st Burst Address A15 – A2 A1 A0
2nd Burst Address A15 – A2 A1 A0
3rd Burst Address A15 – A2 A1 A0

NOTE: The burst wraps around to its initial state upon

completion.

, UW).

(See Note)

A1 A0

MCM67C618B
2

MOTOROLA FAST SRAM

SYNCHRONOUS TRUTH TABLE (See Notes 1, 2, and 3)

ADSP ADSC ADV UW or LW K Address Used Operation

E

H L X X X L–H N/A Deselected
H X L X X L–H N/A Deselected
L L X X X L–H External Address Read Cycle, Begin Burst
L H L X L L–H External Address Write Cycle, Begin Burst
L H L X H L–H External Address Read Cycle, Begin Burst
X H H L L L–H Next Address Write Cycle, Continue Burst
X H H L H L–H Next Address Read Cycle, Continue Burst
X H H H L L–H Current Address Write Cycle, Suspend Burst
X H H H H L–H Current Address Read Cycle, Suspend Burst

NOTES:

1. X means Don’t Care.

2. All inputs except G

3. Wait states are inserted by suspending burst.

must meet setup and hold times for the low–to–high transition of clock (K).

ASYNCHRONOUS TRUTH TABLE (See Notes 1 and 2)

Operation

Read L Data Out
Read H High–Z
Write X High–Z — Data In

Deselected X High–Z

NOTES:

1. X means Don’t Care.

2. For a write operation following a read operation, G
required setup time and held high through the input data hold time.

G I/O Status

must be high before the input data

ABSOLUTE MAXIMUM RATINGS (Voltages Referenced to V

Rating

Power Supply Voltage V
Voltage Relative to VSS for Any

Pin Except V
Output Current (per I/O) I
Power Dissipation P
Temperature Under Bias T
Operating Temperature T
Storage Temperature T

NOTE: Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are

CC

exceeded. Functional operation should be restricted to RECOMMENDED OPER­ATING CONDITIONS. Exposure to higher than recommended voltages for
extended periods of time could affect device reliability.

Symbol Value Unit

CC

Vin, V

– 0.5 to VCC + 0.5 V

out

out

D

bias

A

stg

= 0 V)

SS

– 0.5 to + 7.0 V

± 30 mA

1.6 W

– 10 to + 85 °C

0 to +70 °C

– 55 to + 125 °C

This device contains circuitry to protect the
inputs against damage due to high static volt­ages or electric fields; however, it is advised
that normal precautions be taken to avoid
application of any voltage higher than maxi­mum rated voltages to this high–impedance
circuit.

This BiCMOS memory circuit has been
designed to meet the dc and ac specifications
shown in the tables, after thermal equilibrium
has been established.

This device contains circuitry that will ensure
the output devices are in High–Z at power up.

MOTOROLA FAST SRAM

MCM67C618B

3

DC OPERA TING CONDITIONS AND CHARACTERISTICS

(VCC = 5.0 V ± 5%, TA = 0 to + 70°C, Unless Otherwise Noted)

RECOMMENDED OPERATING CONDITIONS

Parameter

Supply Voltage (Operating Voltage Range) V
Input High Voltage V
Input Low Voltage V

*VIL (min) = – 0.5 V dc; VIL (min) = – 2.0 V ac (pulse width ≤ 20 ns) for I ≤ 20.0 mA.

**VIH (max) = VCC + 0.3 V dc; VIH (max) = VCC + 2.0 V ac (pulse width ≤ 20 ns) for I ≤ 20.0 mA.

(Voltages Referenced to VSS = 0 V)

Symbol Min Max Unit

CC

IH

IL

4.75 5.25 V

2.2 VCC + 0.3** V

– 0.5* 0.8 V

DC CHARACTERISTICS

Parameter Symbol Min Max Unit

Input Leakage Current (All Inputs, Vin = 0 to VCC) I
Output Leakage Current (G = VIH) I
AC Supply Current (G = VIH, E = VIL, I

VIL = 0.0 V and VIH ≥ 3.0 V, Cycle T ime ≥ t

AC Standby Current (E = VIH, I

VIL = 0.0 V and VIH ≥ 3.0 V, Cycle T ime ≥ t
Output Low Voltage (IOL = + 8.0 mA) V
Output High Voltage (IOH = – 4.0 mA) V

NOTE: Good decoupling of the local power supply should always be used. DC characteristics are guaranteed for all possible i486 and Pentium

bus cycles.

out

CAPACITANCE (f = 1.0 MHz, dV = 3.0 V, T

Input Capacitance (All Pins Except DQ0 – DQ17) C
Input/Output Capacitance (DQ0 – DQ17) C

= 0 mA, All Inputs = VIL or VIH,

out

= 0 mA, All Inputs = VIL and V

Parameter

min)

KHKH

min)

KHKH

= 25°C, Periodically Sampled Rather Than 100% Tested)

A

IH,

lkg(I)

lkg(O)

I

CCA5

I

CCA7

I

SB1

OL
OH

Symbol Typ Max Unit

in

I/O

— ± 1.0 µA
— ± 1.0 µA
— 310

290

— 95 mA

— 0.4 V

2.4 3.3 V

4 5 pF
6 8 pF

mA

MCM67C618B
4

MOTOROLA FAST SRAM