MCM44256B Datasheet, PDF (1/8 Pages) Motorola, Inc – 4MB R4000 Secondary Cache Fast Static RAM Module Set

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
4MB R4000 Secondary Cache Fast
Static RAM Module Set
Four MCM44256B modules comprise a full 4 MB of secondary cache for the
R4000 processor. Each module contains nine MCM6729DWJ fast static RAMs
for a cache data size of 256K x 36. The tag portion, dependent on word line size,
contains either two MCM6729DWJ or one MCM6726DWJ fast static RAMs. All
input signals, except A0 and WE are buffered using 74FBT2827 drivers with se-
ries 25 Ω resistors.
The MCM6729DWJ and MCM6726DWJ are fabricated using high–perfor-
mance silicon–gate BiCMOS technology. Static design eliminates the need for
internal clocks or timing strobes.
All 4MB R4000 supported secondary cache options are available.
• Single 5 V ± 10% Power Supply
• All Inputs and Outputs are TTL Compatible
• Fast Module Access Time: 12/15/17 ns
• Zero Wait–State Operation
• Unified or Split Secondary Cache is Supported
• Word Line Sizes of 4, 8, 16, and 32 are Available (See Ordering
Information for Details)
• Decoupling Capacitors are Used for Each Fast Static RAM and Buffer,
Along with Bulk Capacitance for Maximum Noise Immunity
• High Quality Multi–Layer FR4 PWB with Separate Power and Ground
Planes
PIN NAMES
A0 – A17 . . . . . . . . . . . . . . . . Address Inputs
WE . . . . . . . . . . . . . . . . . . . . . . . Write Enable
DCS . . . . . . . . . . . . . . . . . . . . . . Data Enable
TCS . . . . . . . . . . . . . . . . . . . . . . . Tag Enable
OE . . . . . . . . . . . . . . . . . . . . . Output Enable
DQ0 – DQ35 . . . . . . . . . Data Input / Output
TDQ0 – TDQ7 . . . TAG Data Input / Output
VCC . . . . . . . . . . . . . . . . + 5 V Power Supply
VSS . . . . . . . . . . . . . . . . . . . . . . . . . . Ground
For proper operation of the device, VSS must
be connected to ground.
11/19/97
©_MM_Oo_Tto_Orol_Ra,_OInc_L._A19_F97_{AST SRAM}
Order this document
by MCM44256B/D
MCM44256B
Series
PIN ASSIGNMENT
80 LEAD SIMM — TOP VIEW
VCC 2
DQ1 4
DQ3 6
DQ5 8
VSS 10
DQ8 12
DQ10 14
DQ12 16
DQ14 18
DQ15 20
DQ17 22
DQ19 24
DQ21 26
VSS 28
DQ23 30
DQ25 32
DQ27 34
DQ29 36
DQ30 38
DQ32 40
1 VSS
3 DQ0
5 DQ2
7 DQ4
9 DQ6
11 DQ7
13 DQ9
15 DQ11
17 DQ13
19 VSS
21 DQ16
23 DQ18
25 DQ20
27 DQ22
29 VCC
31 DQ24
33 DQ26
35 DQ28
37 VSS
39 DQ31
DQ34 42
VSS 44
A0 46
A2 48
A4 50
A6 52
VCC 54
OE 56
A8 58
A10 60
VSS 62
A13 64
A15 66
A17 68
TDQ0 70
TDQ1 72
TDQ3 74
TDQ5 76
TDQ7 78
VSS 80
41 DQ33
43 DQ35
45 WE
47 A1
49 A3
51 A5
53 VSS
55 DCS
57 A7
59 A9
61 A11
63 A12
65 A14
67 A16
69 TCS
71 VSS
73 TDQ2
75 TDQ4
77 TDQ6
79 VCC
MCM44256B SERIES
1