Motorola MCM67B618AFN10, MCM67B618AFN9 Datasheet

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

64K x 18 Bit BurstRAM
Synchronous Fast Static RAM

With Burst Counter and Self–Timed Write

The MCM67B618A is a 1,179,648 bit synchronous fast 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. 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. 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
triggered noninverting registers.

Bursts can be initiated with either address status processor (ADSP
address status cache controller (ADSC
addresses can be generated internally by the MCM67B618A (burst
sequence imitates that of the i486 and Pentium) and controlled by the burst
address advance (ADV
tailed 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 (L W
able 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 . See Figure 2 for applications information.

• Single 5 V

± 5% Power Supply

• Fast Access Times: 9/10/12 ns Max

• Byte Writeable via Dual Write Enables

• Internal Input Registers (Address, Data, Control)

• 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–

) or

) input pins. Subsequent burst

) input pin. The following pages provide more de-

and UW) are provided to allow individually write-

DQ9

DQ10

V

CC

V

SS
DQ11
DQ12
DQ13
DQ14

V

SS

V

CC
DQ15

DQ16
DQ17

Order this document

by MCM67B618A/D

MCM67B618A

FN PACKAGE

PLASTIC

CASE 778–02

PIN ASSIGNMENTS

A6A7E

7 654 321525150494847

8
9

10
11
12

13
14
15
16
17
18
19
20

21 22 23 24 25 26 27 28 29 30 31 32 33

A4A3A2

A5

UW

LW

A1

ADSC

A0

SS

V

ADSP

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.

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

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

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

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

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

ADV

CC

V

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

K

A15

G

A8A9A10

A13

A14

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

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

A12

46
45

44
43
42
41
40
39
38
37
36
35
34

A11

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

DQ8
DQ7

DQ6
V

CC

V

SS

DQ5
DQ4
DQ3
DQ2
V

SS

V

CC

DQ1
DQ0

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

REV 2
11/5/96

 Motorola, Inc. 1996

MOTOROLA FAST SRAM

MCM67B618A

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

BINARY

16

BURST LOGIC

Q0

A0

COUNTER

Q1

A1

A1 – A0

2

A2 – A15

A0

A1

′

′

INTERNAL
ADDRESS

16

DATA–IN

REGISTERS

9 9

18

64K

×

18

MEMORY

ARRAY

9

OUTPUT
BUFFER

9

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
After the first cycle of the burst, ADV
is advanced prior to the operation. When ADV

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.

controls subsequent burst cycles. When ADV is sampled low, the internal address

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. Write refers to either or both byte write enables (L W

, UW).

BURST SEQUENCE TABLE (See Note)

External Address A15 – A2 A1 A0
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.

MCM67B618A
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

MCM67B618A

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 ≤ 20.0 ns) for I ≤ 20.0 mA.

**VIH (max) = VCC + 0.3 V dc; VIH (max) = VCC + 2.0 V ac (pulse width ≤ 20.0 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

– 0.5* 0.8 V

**

V

DC CHARACTERISTICS AND SUPPLY CURRENTS

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 Time ≥ t

AC Standby Current (E = VIH, I

VIL = 0.0 V and VIH ≥ 3.0 V, Cycle Time ≥ 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

= 0 mA, All Inputs = VIL or VIH,

out

= 0 mA, All Inputs = VIL and V

KHKH

KHKH

min)

min)

IH,

lkg(I)

lkg(O)

I

CCA9

I

CCA10

I

CCA12

I

SB1

OL
OH

— ±1.0 µA
— ±1.0 µA
— 275

265
250

— 95 mA

— 0.4 V

2.4 3.3 V

mA

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

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

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

A

Parameter

Symbol Typ Max Unit

in

I/O

4 5 pF
6 8 pF

MCM67B618A
4

MOTOROLA FAST SRAM