HIGH-SPEED
4K x 16 DUAL-PORT
STATIC RAM
Features
◆
◆
◆
◆
◆
◆
True Dual-Ported memory cells which allow simultaneous
reads of the same memory location
High-speed access
– Commercial: 15/17/20/25/35/55ns (max.)
– Industrial: 20ns (max.)
– Military: 20/25/35/55/70ns (max.)
Low-power operation
– IDT7024S
Active: 750mW (typ.)
Standby: 5mW (typ.)
– IDT7024L
Active: 750mW (typ.)
Standby: 1mW (typ.)
Separate upper-byte and lower-byte control for multiplexed
bus compatibility
◆
◆
◆
◆
◆
◆
◆
◆
◆
7024S/L
IDT7024 easily expands data bus width to 32 bits or more
using the Master/Slave select when cascading more than
one device
M/S = H for BUSY output flag on Master
M/S = L for BUSY input on Slave
Interrupt Flag
On-chip port arbitration logic
Full on-chip hardware support of semaphore signaling
between ports
Fully asynchronous operation from either port
Battery backup operation—2V data retention
TTL-compatible, single 5V (±10%) power supply
Available in 84-pin PGA, Flatpack, PLCC, and 100-pin Thin
Quad Flatpack
Industrial temperature range (–40°C to +85°C) is available
for selected speeds
Green parts available, see ordering information
Functional Block Diagram
R/WL
UBL
R/WR
UBR
LBL
CEL
OEL
LBR
CER
OER
I/O8L-I/O15L
I/O8R-I/O15R
I/O
Control
I/O0L-I/O7L
I/O
Control
I/O0R-I/O7R
(1,2)
(1,2)
BUSYL
A11L
A0L
BUSYR
Address
Decoder
MEMORY
ARRAY
12
CEL
OEL
R/WL
SEML
(2)
INTL
A11R
A0R
12
ARBITRATION
INTERRUPT
SEMAPHORE
LOGIC
M/S
NOTES:
1. (MASTER): BUSY is output; (SLAVE): BUSY is input.
2. BUSY outputs and INT outputs are non-tri-stated push-pull.
CER
OER
R/WR
SEMR
INTR(2)
2740 drw 01
1
Feb.20.20
Address
Decoder
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Description
The IDT7024 is a high-speed 4Kx 16 Dual-Port Static RAM. The
IDT7024 is designed to be used as a stand-alone 64K-bit Dual-Port RAM
or as a combination MASTER/SLAVE Dual-Port RAM for 32-bit or more
word systems. Using the IDT MASTER/SLAVE Dual-Port RAM approach
in 32-bit or wider memory system applications results in full-speed, errorfree operation without the need for additional discrete logic.
This device provides two independent ports with separate control,
address, and I/O pins that permit independent, asynchronous access for
reads or writes to any location in memory. An automatic power down
feature controlled by chip enable (CE) permits the on-chip circuitry of each
port to enter a very low standby power mode.
Fabricated using CMOS high-performance technology, these devices
typically operate on only 750mW of power. Low-power (L) versions offer
battery backup data retention capability with typical power consumption of
500µW from a 2V battery.
The IDT7024 is packaged in a ceramic 84-pin PGA, an 84-pin Flatpack
and PLCC, and a 100-pin TQFP. Military grade product is manufactured
in compliance with the latest revision of MIL-PRF-38535 QML, making it
ideally suited to military temperature applications demanding the highest
level of performance and reliability.
I/O3L
I/O2L
GND
I/O1L
I/O0L
OEL
VCC
R/WL
SEML
CEL
UBL
A11L
77
A10L
A9L
A5R
A6R
A4R
A3R
A2R
A1R
A0R
INTR
M/S
BUSYR
GND
A1L
A0L
A2L
A11R
80
UBL
CEL
48
N/C
81
82
SEML
R/WL
47
46
LBR
UBR
83
84
45
CER
SEMR
VCC
OEL
1
2
I/O0L
I/O1L
3
GND
I/O2L
A10L
A11L
N/C
LBL
7024
FP84(4)
44
43
42
84-Pin Flatpack
Top View
4
41
A7R
A8R
A9R
A10R
GND
R/WR
OER
40
I/O15R
5
6
39
GND
I/O3L
I/O4L
7
8
38
I/O14R
37
I/O5L
9
I/O13R
I/O12R
36
6.42
2
I/O7R
I/O8R
I/O5R
I/O6R
I/O4R
I/O3R
VCC
I/O1R
I/O2R
GND
I/O0R
I/O15L
VCC
I/O14L
I/O13L
GND
I/O12L
I/O11L
I/O8L
35
10
34
11
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
I/O10L
I/O6L
I/O7L
Feb.20.20
A4L
A3L
7574 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 5453
76
52
77
51
78
50
79
49
A8L
A9L
NOTES:
1. All VCC pins must be connected to the power supply.
2. All GND pins must be connected to the ground supply.
3. PLG84 package body is approximately 1.15 in x 1.15 in x .17 in.
FP84 package body is approximately 1.17 in x 1.17 in x .11 in.
4. This package code is used to reference the package diagram.
A5L
A7L
A6L
2740 drw 02J
INTL
BUSYL
A8L
I/O9L
I/O9L
I/O10L
I/O12L
I/O11L
I/O14L
GND
I/O13L
VCC
I/O15L
GND
I/O0R
VCC
I/O2R
I/O1R
I/O3R
I/O4R
I/O5R
I/O8L
I/O4L
78
A6L
A7L
A5L
I/O5L
LBL
N/C
76
53
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 7475
A4L
I/O7L
I/O6L
80
79
52
A6R
A7R
51
A3L
A8R
49
50
A2L
A10R
A9R
48
A1L
N/C
A11R
INTL
A0L
CER
UBR
LBR
BUSYL
SEMR
M/S
R/WR
GND
GND
OER
INTR
BUSYR
GND
I/O15R
A1R
A0R
I/O14R
A3R
A2R
I/O12R
I/O13R
3332 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12
11
34
10
35
9
36
8
37
7
38
6
39
5
40
4
41
3
7024
42
2
PLG84(4)
43
1
44
84
84-Pin PLCC
45
83
Top View
46
82
47
81
A5R
A4R
I/O9R
I/O10R
I/O11R
I/O7R
I/O6R
I/O8R
Pin Configurations(1,2,3)
I/O11R
I/O10R
I/O9R
2740 drw 02F
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
(con't.)
N/C
N/C
N/C
N/C
A5L
A4L
A3L
A2L
A1L
A0L
INTL
BUSYL
GND
M/S
BUSYR
INTR
A0R
A1R
A2R
A3R
A4R
N/C
N/C
N/C
N/C
Pin Configurations
(1,2,3)
75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51
50
76
49
77
78
79
81
46
45
82
83
44
43
84
42
41
80
85
40
86
7024
PNG100(4)
87
88
89
90
91
39
38
37
36
100-Pin TQFP
Top View
92
35
34
93
33
32
94
95
96
31
97
98
29
28
99
100
1 2
A5R
A6R
A7R
A8R
A9R
A10R
A11R
N/C
LBR
UBR
CER
SEMR
GND
R/WR
OER
I/O15R
GND
I/O14R
I/O13R
I/O12R
I/O11R
I/O10R
I/O9R
I/O8R
I/O7R
48
47
30
3
4
5
6
7
8
27
26
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
63
11
61
I/O7L
66
10
I/O10L
67
09
08
2740 drw 03
06
I/O13L
I/O15L
49
I/O1L
50
46
LBL
47
CEL
UBL
53
GND
48
SEML
45
A11L
44
N/C
A9L
VCC
I/O2R
32
GND
VCC
28
A0R
7
GND
I/O7R
1
2
I/O9R
3
I/O11R
A
B
11
5
8
INTR
I/O10R
I/O13R
I/O15R
6
9
C
I/O14R
D
14
OER
E
UBR
R/WR
15
13
22
20
A11R
16
A8R
18
LBR
CER
N/C
F
G
H
J
A3R
24
A6R
19
A10R
A1R
25
A5R
17
BUSYR
27
23
SEMR
GND
10
4
I/O12R
12
A1L
30
A2R
83
I/O8R
M/S
26
I/O4R
I/O6R
36
29
80
I/O5R
INTL
A0L
31
GND
84-Pin PGA
Top View(5)
78
A2L
34
35
BUSYL
7024
GU84(4)
74
GND
I/O3R
A4L
37
A3L
33
A5L
39
A6L
73
I/O14L
I/O1R
A8L
41
R/WL
A7L
40
43
52
VCC
42
A10L
38
77
84
01
51
OEL
I/O12L
I/O0R
82
02
I/O3L
I/O9L
70
81
03
56
57
71
79
04
I/O6L
54
I/O0L
68
76
05
55
I/O2L
59
62
I/O8L
I/O11L
75
NOTES:
1. All VCC pins must be connected to the power supply.
2. All GND pins must be connected to the ground supply.
3. PNG100 package body is approximately 14mm x 14mm x 1.4mm.
4. This package code is used to reference the package diagram.
58
I/O4L
65
72
07
60
I/O5L
64
69
N/C
N/C
N/C
N/C
I/O10L
I/O11L
I/O12L
I/O13L
GND
I/O14L
I/O15L
VCC
GND
I/O0R
I/O1R
I/O2R
VCC
I/O3R
I/O4R
I/O5R
I/O6R
N/C
N/C
N/C
N/C
A6L
A7L
A8L
A9L
A10L
A11L
N/C
LBL
UBL
CEL
SEML
R/WL
VCC
OEL
I/O0L
I/O1L
GND
I/O2L
I/O3L
I/O4L
I/O5L
I/O6L
I/O7L
I/O8L
I/O9L
A4R
21
A9R
K
A7R
L
2740 drw 04
Index
NOTES:
1. All VCC pins must be connected to the power supply.
2. All GND pins must be connected to the ground supply.
3. GU84 package body is approximately 1.12 in x 1.12 in x .16 in.
4. This package code is used to reference the package diagram.
5. This text does not indicate orientation of the actual part-marking.
Pin Names
Left Port
Right Port
Names
CEL
CER
Chip Enable
R/WL
R/WR
Read/Write Enable
OEL
OER
Output Enable
A0L - A11L
A0R - A11R
Address
I/O0L - I/O15L
I/O0R - I/O15R
Data Input/Output
SEML
SEMR
Semaphore Enable
UBL
UBR
Upper Byte Select
LBL
LBR
Lower Byte Select
INTL
INTR
Interrupt Flag
BUSYL
BUSYR
Busy Flag
M/S
Master or Slave Select
VCC
Power
GND
Ground
Maximum Operating Temperature
and Supply Voltage(1)
Grade
Military
Commercial
Industrial
GND
Vcc
-55OC to +125OC
0V
5.0V + 10%
0OC to +70OC
0V
5.0V + 10%
-40OC to +85OC
0V
5.0V + 10%
2740 tbl 02
NOTE:
1. This is the parameter TA. This is the "instant on" case temperature.
2740 tbl 01
6.42
3
Feb.20.20
Ambient
Temperature
,
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Truth Table I: Non-Contention Read/Write Control
Inputs(1)
Outputs
CE
R/W
OE
UB
LB
SEM
I/O8-15
I/O0-7
Mode
H
X
X
X
X
H
High-Z
High-Z
Deselcted: Power-Down
X
X
X
H
H
H
High-Z
High-Z
Both Bytes Deselected
L
L
X
L
H
H
DATAIN
High-Z
Write to Upper Byte Only
L
L
X
H
L
H
High-Z
DATAIN
Write to Lower Byte Only
L
L
X
L
L
H
DATAIN
DATAIN
Write to Both Bytes
L
H
L
L
H
H
DATAOUT
High-Z
Read Upper Byte Only
L
H
L
H
L
H
High-Z
DATA OUT
Read Lower Byte Only
L
H
L
L
L
H
DATAOUT
DATA OUT
Read Both Bytes
X
X
H
X
X
X
High-Z
High-Z
Outputs Disabled
2740 tbl 03
NOTE:
1. A0L — A11L ≠ A0R — A11R
Truth Table II: Semaphore Read/Write Control(1)
Inputs(1)
(2)
Outputs
R/W
OE
UB
LB
SEM
I/O8-15
I/O0-7
H
H
L
X
X
L
DATAOUT
DATAOUT
Read Semaphore Flag Data Out
X
H
L
H
H
L
DATAOUT
DATAOUT
Read Semaphore Flag Data Out
H
↑
X
X
X
L
DATAIN
DATAIN
Write I/O0 into Semaphore Flag
X
↑
X
H
H
L
DATAIN
DATAIN
Write I/O0 into Semaphore Flag
L
X
X
L
X
L
____
____
Not Allowed
L
X
X
X
L
L
____
____
Not Allowed
CE
Mode
2740 tbl 04
NOTE:
1. There are eight semaphore flags written to via I/O0 and read from all of the I/O's (I/O0 - I/O15).
These eight semaphores are addressed by A0 - A2.
Recommended DC Operating
Conditions
Absolute Maximum Ratings(1)
Symbol
Rating
Commercial
& Industrial
Military
Unit
Symbol
VTERM(2)
Terminal Voltage
with Respect
to GND
-0.5 to +7.0
-0.5 to +7.0
V
TBIAS
Temperature
Under Bias
-55 to +125
-65 to +135
o
C
TSTG
Storage
Temperature
-65 to +150
-65 to +150
o
C
IOUT
DC Output
Current
50
50
2740 tbl 05
6.42
4
Min.
Typ.
Max.
Unit
4.5
5.0
5.5
V
0
0
0
V
V
VCC
Supply Voltage
GND
Ground
VIH
Input High Voltage
2.2
____
6.0(2)
VIL
Input Low Voltage
-0.5(1)
____
0.8
NOTES:
1. VIL > -1.5V for pulse width less than 10ns.
2. VTERM must not exceed Vcc + 10%.
mA
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS
may cause permanent damage to the device. This is a stress rating only
and functional operation of the device at these or any other conditions above
those indicated in the operational sections of this specification is not implied.
Exposure to absolute maximum rating conditions for extended periods may
affect reliability.
2. VTERM must not exceed Vcc +10% for more than 25% of the cycle time or 10ns
maximum, and is limited to < 20mA for the period over VTERM > Vcc + 10%.
Feb.20.20
Parameter
V
2740 tbl 06
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Capacitance (TA = +25°C, f = 1.0MHz)
Symbol
CIN
COUT
Parameter
Input Capacitance
Output Capacitance
(1)
Conditions(2)
Max.
Unit
VIN = 3dV
9
pF
VOUT = 3dV
10
pF
2740 tbl 07
NOTES:
1. This parameter are determined by device characterization, but is not
production tested.
2. 3dV references the interpolated capacitance when the input and
output signals switch from 0V to 3V or from 3V to 0V.
DC Electrical Characteristics Over the Operating
Temperature and Supply Voltage Range (VCC = 5.0V ± 10%)
7024S
Symbol
Parameter
Min.
Max.
Min.
Max.
Unit
VCC = 5.5V, VIN = 0V to V CC
___
10
___
5
µA
Output Leakage Current
CE = VIH, VOUT = 0V to V CC
___
10
___
5
µA
VOL
Output Low Voltage
IOL = +4mA
___
0.4
___
0.4
V
VOH
Output High Voltage
IOH = -4mA
2.4
___
2.4
___
|ILI|
(1)
Input Leakage Current
|ILO|
Test Conditions
7024L
V
2740 tbl 08
NOTE:
1. At Vcc < 2.0V input leakages are undefined.
DC Electrical Characteristics Over the Operating
Temperature and Supply Voltage Range(1) (VCC = 5.0V ± 10%)
7024X15
Com'l Only
Symbol
ICC
ISB1
ISB2
ISB3
ISB4
Parameter
Dynamic Operating
Current
(Both Ports Active)
Standby Current
(Both Ports - TTL
Level Inputs)
Standby Current
(One Port - TTL
Level Inputs)
Full Standby Current
(Both Ports CMOS Level Inputs)
Full Standby Current
(One Port CMOS Level Inputs)
Test Condition
Version
7024X17
Com'l Only
7024X20
Com'l, Ind
& Military
7024X25
Com'l &
Military
Typ. (2)
Max.
Typ.(2)
Max.
Typ.(2)
Max.
Typ.(2)
Max.
Unit
mA
CE = VIL,
Outputs Disabled
SEM = VIH
f = fMAX(3)
COM'L
S
L
170
170
310
260
170
170
310
260
160
160
290
240
155
155
265
220
MIL &
IND
S
L
____
____
____
____
____
____
____
____
160
160
370
320
155
155
340
280
CER = CEL = VIH
SEMR = SEML = VIH
f = fMAX(3)
COM'L
S
L
20
20
60
50
20
20
60
50
20
20
60
50
16
16
60
50
MIL &
IND
S
L
____
____
____
____
____
____
____
____
20
20
90
70
16
16
80
65
COM'L
S
L
105
105
190
160
105
105
190
160
95
95
180
150
90
90
170
140
MIL &
IND
S
L
____
____
____
____
____
____
____
____
95
95
240
210
90
90
215
180
COM'L
S
L
1.0
0.2
15
5
1.0
0.2
15
5
1.0
0.2
15
5
1.0
0.2
15
5
MIL &
IND
S
L
____
____
____
____
____
____
____
____
1.0
0.2
30
10
1.0
0.2
30
10
COM'L
S
L
100
100
170
140
100
100
170
140
90
90
155
130
85
85
145
120
MIL &
IND
S
L
____
____
____
____
____
____
____
____
90
90
225
200
85
85
200
170
CE"A" = VIL and CE"B" = VIH(5)
Active Port Outputs Disabled,
f=fMAX(3)
SEMR = SEML = VIH
Both Ports CEL and
CER > VCC - 0.2V,
VIN > VCC - 0.2V or
VIN < 0.2V, f = 0(4)
SEMR = SEML > VCC - 0.2V
CE"A" < 0.2V and
CE"B" > VCC - 0.2V(5)
SEMR = SEML > VCC - 0.2V
VIN > VCC - 0.2V or V IN < 0.2V
Active Port Outputs Disabled,
f = fMAX(3)
mA
mA
mA
mA
2740 tbl 09a
NOTES:
1. 'X' in part number indicates power rating (S or L)
2. VCC = 5V, TA = +25°C, and are not production tested. ICC DC = 120mA (TYP.)
3. At f = fMAX, address and I/O'S are cycling at the maximum frequency read cycle of 1/tRC, and using “AC Test Conditions” of input levels of GND to 3V.
4. f = 0 means no address or control lines change.
5. Port "A" may be either left or right port. Port "B" is the opposite from port "A".
6.42
5
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
DC Electrical Characteristics Over the Operating
Temperature and Supply Voltage Range(1) (con’t.)
(VCC = 5.0V ± 10%)
7024X35
Com'l &
Military
Symbol
ICC
ISB1
ISB2
ISB3
ISB4
Parameter
Test Condition
Dynamic Operating
Current
(Both Ports Active)
CE = VIL,
Outputs Disabled
SEM = VIH
f = fMAX(3)
Standby Current
(Both Ports - TTL
Level Inputs)
CER = CEL = VIH
SEMR = SEML = VIH
f = fMAX(3)
Standby Current
(One Port - TTL
Level Inputs)
CE"A" = VIL and CE"B" = VIH(5)
Active Port Outputs Disabled,
f=fMAX(3)
SEMR = SEML = VIH
Full Standby Current
(Both Ports CMOS Level Inputs)
Both Ports CEL and
CER > VCC - 0.2V,
VIN > VCC - 0.2V or
VIN < 0.2V, f = 0(4)
SEMR = SEML > VCC - 0.2V
Full Standby Current
(One Port CMOS Level Inputs)
CE"A" < 0.2V and
CE"B" > VCC - 0.2V(5)
SEMR = SEML > VCC - 0.2V
VIN > VCC - 0.2V or V IN < 0.2V
Active Port Outputs Disabled,
f = fMAX(3)
Version
7024X55
Com'l, Ind
& Military
7024X70
Military Only
Typ.(2)
Max.
Typ.(2)
Max.
Typ.(2)
Max.
Unit
____
mA
COM'L
S
L
150
150
250
210
150
150
250
210
____
____
____
MIL &
IND
S
L
150
150
300
250
150
150
300
250
140
140
300
250
COM'L
S
L
13
13
60
50
13
13
60
50
____
____
____
____
MIL &
IND
S
L
13
13
80
65
13
13
80
65
10
10
80
65
COM'L
S
L
85
85
155
130
95
95
155
130
____
____
____
____
MIL &
IND
S
L
85
85
190
160
95
95
190
160
80
80
190
160
COM'L
S
L
1.0
0.2
15
5
1.0
0.2
15
5
____
____
____
____
MIL &
IND
S
L
1.0
0.2
30
10
1.0
0.2
30
10
1.0
0.2
30
10
COM'L
S
L
80
80
135
110
80
80
135
110
____
____
____
____
MIL &
IND
S
L
80
80
175
150
80
80
175
150
75
75
175
150
NOTES:
1. 'X' in part number indicates power rating (S or L)
2. VCC = 5V, TA = +25°C, and are not production tested.
3. At f = fMAX, address and I/O'S are cycling at the maximum frequency read cycle of 1/tRC, and using “AC Test Conditions”of input levels of GND to 3V.
4. f = 0 means no address or control lines change.
5. Port "A" may be either left or right port. Port "B" is the opposite from port "A".
mA
mA
mA
mA
2740 tbl 09b
Data Retention Characteristics Over All Temperature Ranges
(L Version Only) (VLC = 0.2V, VHC = VCC - 0.2V)(4)
Symbol
Parameter
Test Condition
Min.
Typ.(1)
Max.
Unit
2.0
___
___
V
µA
VDR
VCC for Data Retention
VCC = 2V
ICCDR
Data Retention Current
CE > VHC
MIL. & IND.
___
100
4000
VIN > VHC or < VLC
COM'L.
___
100
1500
0
___
___
ns
tRC(2)
___
___
ns
tCDR
(3)
tR(3)
Chip Deselect to Data Retention Time
SEM > VHC
Operation Recovery Time
NOTES:
1. TA = +25°C, VCC = 2V, and are by device characterization but are not production tested.
2. tRC = Read Cycle Time
3. This parameter is guaranteed but not tested.
4. At Vcc < 2.0V, input leakages are not defined.
6.42
6
Feb.20.20
2740 tbl 10
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Data Retention Waveform
DATA RETENTION MODE
VDR ≥ 2V
4.5V
VCC
4.5V
tCDR
tR
VDR
VIH
CE
VIH
2740 drw 05
AC Test Conditions
Input Pulse Levels
GND to 3.0V
Input Rise/Fall Times
5ns
Input Timing Reference Levels
1.5V
Output Reference Levels
1.5V
Output Load
Figures 1 and 2
2740 tbl 11
5V
5V
1250Ω
DATAOUT
BUSY
INT
1250Ω
DATAOUT
775Ω
30pF
775Ω
5pF*
2740 drw 06
Figure 1. AC Output Test Load
Figure 2. Output Test Load
(for tLZ, tHZ, tWZ, tOW)
*Including scope and Jig
6.42
7
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(4)
7024X15
Com'l Only
Symbol
Parameter
7024X17
Com'l Only
7024X20
Com'l, Ind
& Military
7024X25
Com'l &
Military
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
READ CYCLE
tRC
Read Cycle Time
15
____
17
____
20
____
25
____
ns
tAA
Address Access Time
____
15
____
17
____
20
____
25
ns
Chip Enable Access Time
(3)
____
15
____
17
____
20
____
25
ns
tABE
Byte Enable Access Time
(3)
____
15
____
17
____
20
____
25
ns
tAOE
Output Enable Access Time
____
10
____
10
____
12
____
13
ns
tOH
Output Hold from Address Change
3
____
3
____
3
____
3
____
ns
3
____
3
____
3
____
3
____
ns
____
10
____
10
____
12
____
15
ns
0
____
0
____
0
____
0
____
ns
____
15
____
17
____
20
____
25
ns
10
____
10
____
10
____
10
____
ns
____
15
____
17
____
20
____
25
ns
tACE
tLZ
Output Low-Z Time
tHZ
(1,2)
Output High-Z Time
(1,2)
(1,2)
tPU
Chip Enable to Power Up Time
tPD
Chip Disable to Power Down Time (1,2)
tSOP
Semaphore Flag Update Pulse (OE or SEM)
tSAA
Semaphore Address Access
(3)
2740 tbl 12a
7024X35
Com'l &
Military
Symbol
Parameter
7024X55
Com'l, Ind
& Military
7024X70
Military Only
Min.
Max.
Min.
Max.
Min.
Max.
Unit
35
____
55
____
70
____
ns
READ CYCLE
tRC
Read Cycle Time
tAA
Address Access Time
____
35
____
55
____
70
ns
Chip Enable Access Time
(3)
____
35
____
55
____
70
ns
tABE
Byte Enable Access Time
(3)
____
35
____
55
____
70
ns
tAOE
Output Enable Access Time
____
20
____
30
____
35
ns
tOH
Output Hold from Address Change
3
____
3
____
3
____
ns
tLZ
Output Low-Z Time (1,2)
3
____
3
____
3
____
ns
tHZ
(1,2)
____
15
____
25
____
30
ns
0
____
0
____
0
____
ns
____
35
____
50
____
50
ns
15
____
15
____
15
____
ns
____
35
____
55
____
70
tACE
tPU
Output High-Z Time
Chip Enab le to Power Up Time
(1,2)
(1,2)
tPD
Chip Disable to Power Down Time
tSOP
Semaphore Flag Update Pulse (OE or SEM)
tSAA
Semaphore Address Access
(3)
NOTES:
1. Transition is measured 0mV from Low or High-impedance voltage with the Output Test Load (Figure 2).
2. This parameter is guaranteed by device characterization, but is not production tested.
3. To access RAM, CE = VIL, UB or LB = VIL, and SEM =VIH. To access semaphore, CE = VIH or UB & LB = VIH, and SEM =VIL.
4. 'X' in part number indicates power rating (S or L).
6.42
8
Feb.20.20
ns
2740 tbl 12b
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Waveform of Read Cycles
(5)
tRC
ADDR
(4)
tAA
(4)
tACE
CE
tAOE
(4)
OE
tABE
(4)
UB, LB
R/W
tOH
tLZ (1)
(4)
DATAOUT
VALID DATA
tHZ (2)
BUSYOUT
tBDD
(3,4)
2740 drw 07
NOTES:
1. Timing depends on which signal is asserted last, CE, OE, LB, or UB.
2. Timing depends on which signal is de-asserted first, CE, OE, LB, or UB.
3. tBDD delay is required only in cases where opposite port is completing a write operation to the same address location. For simultaneous read operations BUSY has
no relation to valid output data.
4. Start of valid data depends on which timing becomes effective last tABE, tAOE, tACE, tAA or tBDD.
5. SEM = VIH.
Timing of Power-Up Power-Down
CE
ICC
tPU
tPD
ISB
,
2740 drw 08
6.42
9
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage(5)
7024X15
Com'l Only
Symbol
Parameter
7024X17
Com'l Only
7024X25
Com'l &
Military
7024X20
Com'l, Ind
& Military
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
WRITE CYCLE
tWC
Write Cycle Time
15
____
17
____
20
____
25
____
ns
tEW
Chip Enable to End-of-Write (3)
12
____
12
____
15
____
20
____
ns
tAW
Address Valid to End-of-Write
12
____
12
____
15
____
20
____
ns
0
____
0
____
0
____
0
____
ns
ns
(3)
tAS
Address Set-up Time
tWP
Write Pulse Width
12
____
12
____
15
____
20
____
tWR
Write Recovery Time
0
____
0
____
0
____
0
____
ns
tDW
Data Valid to End-of-Write
10
____
10
____
15
____
15
____
ns
____
10
____
10
____
12
____
15
ns
0
____
0
____
0
____
0
____
ns
____
Output High-Z Time
tHZ
Data Hold Time
tDH
(1,2)
(4)
(1,2)
tWZ
Write Enab le to Output in High-Z
10
____
10
____
12
____
15
ns
tOW
Output Active from End-of-Write (1,2,4)
0
____
0
____
0
____
0
____
ns
tSWRD
SEM Flag Write to Read Time
5
____
5
____
5
____
5
____
ns
tSPS
SEM Flag Contention Window
5
____
5
____
5
____
5
____
ns
2740 tbl 13a
7024X35
Com'l &
Military
Symbol
Parameter
7024X55
Com'l, Ind
& Military
7024X70
Military Only
Min.
Max.
Min.
Max.
Min.
Max.
Unit
WRITE CYCLE
tWC
Write Cycle Time
35
____
55
____
70
____
ns
tEW
Chip Enable to End-of-Write
(3)
30
____
45
____
50
____
ns
tAW
Address Valid to End-of-Write
30
____
45
____
50
____
ns
tAS
Address Set-up Time (3)
0
____
0
____
0
____
ns
tWP
Write Pulse Width
25
____
40
____
50
____
ns
tWR
Write Recovery Time
0
____
0
____
0
____
ns
tDW
Data Valid to End-of-Write
15
____
30
____
40
____
ns
____
15
____
25
____
30
ns
0
____
0
____
0
____
ns
(1,2)
____
15
____
25
____
30
ns
(1,2,4)
0
____
0
____
0
____
ns
5
____
5
____
ns
5
____
5
____
tHZ
Output High-Z Time
tDH
Data Hold Time (4)
tWZ
(1,2)
Write Enab le to Output in High-Z
tOW
Output Active from End-of-Write
tSWRD
SEM Flag Write to Read Time
5
____
SEM Flag Contention Window
5
____
tSPS
NOTES:
1. Transition is measured 0mV from Low or High-impedance voltage with the Output Test Load (Figure 2).
2. This parameter is guaranteed by device characterization, but is not production tested.
3. To access RAM, CE = VIL, UB or LB = VIL, SEM = VIH. To access semaphore, CE = VIH or UB & LB = VIH, and SEM = VIL.
Either condition must be valid for the entire tEW time.
4. The specification for tDH must be met by the device supplying write data to the RAM under all operating conditions. Although tDH
and tOW values will vary over voltage and temperature, the actual tDH will always be smaller than the actual tOW.
5. 'X' in part number indicates power rating (S or L).
6.42
10
Feb.20.20
ns
2740 tbl 13b
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Timing Waveform of Write Cycle No. 1, R/W Controlled Timing(1,5,8)
tWC
ADDRESS
tHZ (7)
OE
tAW
(9)
CE or SEM
(9)
UB or LB
tWP (2)
tAS (6)
tWR
(3)
R/W
tWZ
(7)
tOW
(4)
DATAOUT
(4)
tDW
tDH
DATAIN
2740 drw 09
Timing Waveform of Write Cycle No. 2, CE, UB, LB Controlled Timing(1,5)
tWC
ADDRESS
tAW
(9)
CE or SEM
tAS(6)
tWR (3)
tEW (2)
(9)
UB or LB
R/W
tDW
tDH
DATAIN
2740 drw 10
NOTES:
1. R/W or CE or UB & LB = VIH during all address transitions.
2. A write occurs during the overlap (tEW or tWP) of a UB or LB = VIL and a CE = VIL and a R/W = VIL for memory array writing cycle.
3. tWR is measured from the earlier of CE or R/W (or SEM or R/W) going HIGH = VIL to the end-of-write cycle.
4. During this period, the I/O pins are in the output state and input signals must not be applied.
5. If the CE or SEM LOW = VIL transition occurs simultaneously with or after the R/W = VIL transition, the outputs remain in the High-impedance state.
6. Timing depends on which enable signal is asserted last, CE, R/W, UB, or LB.
7. This parameter is guaranteed by device characterization, but is not production tested. Transition is measured 0mV steady state with the Output Test Load
(Figure 2).
8. If OE = VIL during R/W controlled write cycle, the write pulse width must be the larger of tWP for (tWZ + tDW) to allow the I/O drivers to turn off and data to be
placed on the bus for the required tDW. If OE = VIH during an R/W controlled write cycle, this requirement does not apply and the write pulse can be as short as the
specified tWP .
9. To access RAM, CE = VIL, UB or LB = VIL, and SEM = VIH. To access Semaphore, CE = VIH or UB & LB = VIH, and SEM = VIL. tEW must be
met for either condition.
6.42
11
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Timing Waveform of Semaphore Read after Write Timing, Either Side(1)
tOH
tSAA
A0-A2
VALID ADDRESS
tWR
tAW
tEW
VALID ADDRESS
tACE
SEM
tSOP
tDW
DATAIN
VALID
I/O0
tAS
tWP
DATAOUT
VALID(2)
tDH
R/W
tSWRD
tAOE
OE
Write Cycle
Read Cycle
2740 drw 11
NOTES:
1. CE = VIH or UB & LB = VIH for the duration of the above timing (both write and read cycle).
2. “DATAOUT VALID” represents all I/O's (I/O0-I/O15) equal to the semaphore value.
Timing Waveform of Semaphore Write Contention(1,3,4)
A0"A"-A2"A"
(2)
SIDE
"A"
MATCH
R/W"A"
SEM"A"
tSPS
A0"B"-A2"B"
(2)
SIDE
"B"
MATCH
R/W"B"
SEM"B"
2740 drw 12
NOTES:
1. D0R = D0L = VIL, CER = CEL = VIH, or both UB & LB = VIH, semaphore flag is released from both sides (reads as ones from both sides) at cycle start.
2. All timing is the same for left and right ports. Port “A” may be either left or right port. Port “B” is the opposite from port “A”.
3. This parameter is measured from R/WA or SEMA going HIGH to R/WB or SEMB going HIGH.
4. If tSPS is not satisfied, there is no guarantee which side will obtain the semaphore flag.
6.42
12
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(6)
7024X15
Com'l Only
Symbol
Parameter
7024X17
Com'l Only
7024X20
Com'l, Ind
& Military
7024X25
Com'l &
Military
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
BUSY Access Time from Address Match
____
15
____
17
____
20
____
20
ns
BUSY Disable Time from Address Not Match
____
15
____
17
____
20
____
20
ns
BUSY Access Time from Chip Enable Low
____
15
____
17
____
20
____
20
ns
BUSY Disable Time from Chip Enable High
____
15
____
17
____
17
____
17
ns
5
____
5
____
5
____
5
____
ns
BUSY TIMING (M/S = VIH)
tBAA
tBDA
tBAC
tBDC
tAPS
Arbitration Priority Set-up Time
(2)
(3)
tBDD
BUSY Disable to Valid Data
____
18
____
18
____
30
____
30
ns
tWH
Write Hold After BUSY(5)
12
____
13
____
15
____
17
____
ns
0
____
0
____
0
____
0
____
ns
12
____
13
____
15
____
17
____
ns
BUSY INPUT TIMING (M/S = VIH)
BUSY Input to Write (4)
tWB
tWH
(5)
Write Hold After BUSY
PORT-TO-PORT DELAY TIMING
tWDD
Write Pulse to Data Delay(1)
____
30
____
30
____
45
____
50
ns
tDDD
Write Data Valid to Read Data Delay (1)
____
25
____
25
____
35
____
35
ns
2740 tbl 14a
7024X35
Com'l &
Military
Symbol
Parameter
7024X55
Com'l, Ind
& Military
7024X70
Military Only
Min.
Max.
Min.
Max.
Min.
Max.
Unit
BUSY Access Time from Address Match
____
20
____
45
____
45
ns
BUSY TIMING (M/S = VIH)
tBAA
BUSY Disable Time from Address Not Match
____
20
____
40
____
40
ns
tBAC
BUSY Access Time from Chip Enable Low
____
20
____
40
____
40
ns
tBDC
BUSY Disable Time from Chip Enable High
____
20
____
35
____
35
ns
tAPS
Arbitration Priority Set-up Time (2)
tBDD
BUSY Disable to Valid Data(3)
tBDA
tWH
(5)
Write Hold After BUSY
5
____
5
____
5
____
ns
____
35
____
40
____
45
ns
25
____
25
____
25
____
ns
BUSY INPUT TIMING (M/S = VIH)
tWB
BUSY Input to Write (4)
0
____
0
____
0
____
ns
tWH
Write Hold After BUSY(5)
25
____
25
____
25
____
ns
____
60
____
80
____
95
ns
____
45
____
65
____
80
PORT-TO-PORT DELAY TIMING
tWDD
tDDD
Write Pulse to Data Delay(1)
Write Data Valid to Read Data Delay
(1)
NOTES:
1. Port-to-port delay through RAM cells from writing port to reading port, refer to "Timing Waveform of Write Port-to-Port Read and BUSY (M/S = VIH)".
2. To ensure that the earlier of the two ports wins.
3. tBDD is a calculated parameter and is the greater of 0ns, tWDD – tWP (actual) or tDDD – tDW (actual).
4. To ensure that the write cycle is inhibited on port 'B' during contention with port 'A'.
5. To ensure that a write cycle is completed on port 'B' after contention with port 'A'.
6. 'X' in part number indicates power rating (S or L).
6.42
13
Feb.20.20
ns
2740 tbl 14b
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Timing Waveform of Write with Port-to-Port Read and BUSY(2,4,5) (M/S = VIH)
tWC
MATCH
ADDR"A"
tWP
R/W"A"
tDH
tDW
VALID
DATAIN "A"
tAPS
(1)
MATCH
ADDR"B"
tBAA
tBDA
tBDD
BUSY"B"
tWDD
DATAOUT "B"
VALID
tDDD (3)
NOTES:
1. To ensure that the earlier of the two ports wins. tAPS is ignored for M/S = VIL (SLAVE).
2. CEL = CER = VIL.
3. OE = VIL for the reading port.
4. If M/S = VIL (slave) then BUSY is an input BUSY"A" = VIL and BUSY"B" = don't care, for this example.
5. All timing is the same for both left and right ports. Port "A" may be either the left or right port. Port "B" is the port opposite from port "A".
Timing Waveform of Write with BUSY
tWP
R/W"A"
tWB(3)
BUSY"B"
tWH
R/W"B"
(1)
,
(2)
2740 drw 14
NOTES:
1. tWH must be met for both BUSY input (slave) and output (master).
2. BUSY is asserted on port "B" Blocking R/W"B", until BUSY"B" goes HIGH.
3. tWB is only for the 'Slave' Version.
6.42
14
Feb.20.20
2740 drw 13
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Waveform of BUSY Arbitration Controlled by CE Timing(1) (M/S = VIH)
ADDR"A"
and "B"
ADDRESSES MATCH
CE"A"
tAPS (2)
CE"B"
tBAC
tBDC
BUSY"B"
2740 drw 15
Waveform of BUSY Arbitration Cycle Controlled by Address Match
Timing(1) (M/S = VIH)
ADDR"A"
ADDRESS "N"
tAPS
(2)
ADDR"B"
MATCHING ADDRESS "N"
tBAA
tBDA
BUSY"B"
2740 drw 16
NOTES:
1. All timing is the same for left and right ports. Port “A” may be either the left or right port. Port “B” is the port opposite from “A”.
2. If tAPS is not satisfied, the BUSY signal will be asserted on one side or another but there is no guarantee on which side BUSY will be asserted.
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(1)
7024X15
Com'l Only
Symbol
Parameter
7024X17
Com'l Only
7024X20
Com'l , Ind
& Military
7024X25
Com'l &
Military
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
0
____
0
____
0
____
0
____
ns
INTERRUPT TIMING
tAS
Address Set-up Time
tWR
Write Recovery Time
tINS
tINR
0
____
0
____
0
____
0
____
ns
Interrupt Set Time
____
15
____
15
____
20
____
20
ns
Interrupt Reset Time
____
15
____
15
____
20
____
20
ns
2740 tbl 15a
7024X35
Com'l &
Military
Symbol
Parameter
7024X55
Com'l, Ind
& Military
7024X70
Military Only
Min.
Max.
Min.
Max.
Min.
Max.
Unit
INTERRUPT TIMING
tAS
Address Set-up Time
0
____
0
____
0
____
ns
tWR
Write Recovery Time
0
____
0
____
0
____
ns
tINS
Interrupt Set Time
____
25
____
40
____
50
ns
tINR
Interrupt Reset Time
____
25
____
40
____
50
ns
2740 tbl 15b
NOTES:
1. 'X' in part number indicates power rating (S or L).
6.42
15
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Waveform of Interrupt Timing(1)
tWC
ADDR"A"
INTERRUPT SET ADDRESS
(2)
tAS (3)
tWR
(4)
CE"A"
R/W"A"
tINS (3)
INT"B"
2740 drw 17
tRC
INTERRUPT CLEAR ADDRESS
ADDR"B"
tAS
(2)
(3)
CE"B"
OE"B"
tINR(3)
INT"B"
2740 drw 18
NOTES:
1. All timing is the same for left and right ports. Port “A” may be either the left or right port. Port “B” is the port opposite from “A”.
2. See Interrupt Truth Table III.
3. Timing depends on which enable signal (CE or R/W) is asserted last.
4. Timing depends on which enable signal (CE or R/W) is de-asserted first.
Truth Table III — Interrupt Flag(1,4)
Left Port
R/WL
L
X
X
X
CEL
L
X
X
L
OEL
X
X
X
L
Right Port
A11L-A0L
FFF
X
X
FFE
INTL
X
R/WR
X
CER
X
X
A11R-A0R
X
INTR
Function
(2)
Set Right INTR Flag
(3)
L
X
L
L
FFF
H
Reset Right INTR Flag
(3)
L
L
X
FFE
X
Set Left INTL Flag
(2)
X
X
X
X
X
Reset Left INTL Flag
X
L
H
2740 tbl 16
NOTES:
1. Assumes BUSYL = BUSYR = VIH.
2. If BUSYL = VIL, then no change.
3. If BUSYR = VIL, then no change.
4. INTR and INTL must be initialized at power-up.
6.42
16
Feb.20.20
OER
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Truth Table IV —
Address BUSY Arbitration
Inputs
Outputs
CEL
CER
A0L-A11L
A0R-A11R
BUSYL(1)
BUSYR(1)
Function
X
X
NO MATCH
H
H
Normal
H
X
MATCH
H
H
Normal
X
H
MATCH
H
H
Normal
L
L
MATCH
(2)
(2)
Write Inhibit(3)
2740 tbl 17
NOTES:
1. Pins BUSYL and BUSYR are both outputs when the part is configured as a master. Both are inputs when configured as a slave. BUSYX outputs on the IDT7024 are
push pull, not open drain outputs. On slaves, the BUSY asserted input internally inhibits write.
2. "L" if the inputs to the opposite port were stable prior to the address and enable inputs of this port. "H" if the inputs to the opposite port became stable after the address
and enable inputs of this port. If tAPS is not met, either BUSYL or BUSYR = LOW will result. BUSYL and BUSYR outputs cannot be LOW simultaneously.
3. Writes to the left port are internally ignored when BUSYL outputs are driving LOW regardless of actual logic level on the pin. Writes to the right port are internally ignored
when BUSYR outputs are driving LOW regardless of actual logic level on the pin.
Truth Table V — Example of Semaphore Procurement Sequence(1,2,3)
Functions
D0 - D15 Left
D0 - D15 Right
Status
No Action
1
1
Semaphore free
Left Port Writes "0" to Semaphore
0
1
Left port has semaphore token
Right Port Writes "0" to Semaphore
0
1
No change. Right side has no write access to semaphore
Left Port Writes "1" to Semaphore
1
0
Right port obtains semaphore token
Left Port Writes "0" to Semaphore
1
0
No change. Left port has no write access to semaphore
Right Port Writes "1" to Semaphore
0
1
Left port obtains semaphore token
Left Port Writes "1" to Semaphore
1
1
Semaphore free
Right Port Writes "0" to Semaphore
1
0
Right port has semaphore token
Right Port Writes "1" to Semaphore
1
1
Semaphore free
Left Port Writes "0" to Semaphore
0
1
Left port has semaphore token
Left Port Writes "1" to Semaphore
1
1
Semaphore free
NOTES:
1. This table denotes a sequence of events for only one of the eight semaphores on the IDT7024.
2. There are eight semaphore flags written to via I/O0 and read from all the I/O's. These eight semaphores are addressed by A0-A2.
3. CE = VIH, SEM = VIL, to access the Semaphores. Refer to the Semaphore Read/Write Control Truth Table.
2740 tbl 18
Functional Description
The IDT7024 provides two ports with separate control, address and
I/O pins that permit independent access for reads or writes to any location
in memory. The IDT7024 has an automatic power down feature controlled
by CE. The CE controls on-chip power down circuitry that permits the
respective port to go into a standby mode when not selected (CE = VIH).
When a port is enabled, access to the entire memory array is permitted.
Interrupts
If the user chooses the interrupt function, a memory location (mail box
or message center) is assigned to each port. The left port interrupt flag
(INTL) is asserted when the right port writes to memory location FFE
(HEX), where a write is defined as the CE = R/W = VIL per the Truth Table
III. The left port clears the interrupt by access address location FFE access
when CER = OER = VIL, R/W is a "don't care". Likewise, the right port
interrupt flag (INTR) is asserted when the left port writes to memory location
FFF (HEX) and to clear the interrupt flag (INTR), the right port must access
the memory location FFF. The message (16 bits) at FFE or FFF is userdefined, since it is an addressable SRAM location. If the interrupt function
6.42
17
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
is not used, address locations FFE and FFF are not used as mail boxes,
but as part of the random access memory. Refer to Truth Table III for the
interrupt operation.
Busy Logic
Busy Logic provides a hardware indication that both ports of the RAM
have accessed the same location at the same time. It also allows one of the
two accesses to proceed and signals the other side that the RAM is “busy”.
The BUSY pin can then be used to stall the access until the operation on
the other side is completed. If a write operation has been attempted from
the side that receives a BUSY indication, the write signal is gated internally
to prevent the write from proceeding.
The use of BUSY logic is not required or desirable for all applications.
In some cases it may be useful to logically OR the BUSY outputs together
and use any BUSY indication as an interrupt source to flag the event of
an illegal or illogical operation. If the write inhibit function of BUSY logic is
not desirable, the BUSY logic can be disabled by placing the part in slave
mode with the M/S pin. Once in slave mode the BUSY pin operates solely
as a write inhibit input pin. Normal operation can be programmed by tying
the BUSY pins HIGH. If desired, unintended write operations can be
prevented to a port by tying the BUSY pin for that port LOW.
The BUSY outputs on the IDT 7024 SRAM in master mode, are pushpull type outputs and do not require pull up resistors to operate. If these
RAMs are being expanded in depth, then the BUSY indication for the
resulting array requires the use of an external AND gate.
Width Expansion with BUSY Logic
Master/Slave Arrays
When expanding an IDT7024 RAM array in width while using BUSY
logic, one master part is used to decide which side of the RAM array will
receive a BUSY indication, and to output that indication. Any number of
slaves to be addressed in the same address range as the master, use
the BUSY signal as a write inhibit signal. Thus on the IDT7024 RAM the
BUSY pin is an output if the part is used as a master (M/S pin = VIH), and
the BUSY pin is an input if the part used as a slave (M/S pin = VIL) as shown
in Figure 3.
If two or more master parts were used when expanding in width, a split
decision could result with one master indicating BUSY on one side of the
array and another master indicating BUSY on one other side of the array.
This would inhibit the write operations from one port for part of a word and
inhibit the write operations from the other port for the other part of the word.
The BUSY arbitration, on a master, is based on the chip enable and
address signals only. It ignores whether an access is a read or write. In
a master/slave array, both address and chip enable must be valid long
enough for a BUSY flag to be output from the master before the actual write
pulse can be initiated with either the R/W signal or the byte enables. Failure
to observe this timing can result in a glitched internal write inhibit signal and
corrupted data in the slave.
Semaphores
The IDT7024 is an extremely fast Dual-Port 4K x 16 CMOS Static RAM
with an additional 8 address locations dedicated to binary semaphore flags.
These flags allow either processor on the left or right side of the Dual-Port
RAM to claim a privilege over the other processor for functions defined by
the system designer’s software. As an example, the semaphore can be
BUSY (L)
CE
SLAVE
Dual Port
RAM
BUSY (L) BUSY (R)
MASTER
CE
Dual Port
RAM
BUSY (L) BUSY (R)
SLAVE
CE
Dual Port
RAM
BUSY (L) BUSY (R)
BUSY (R)
2740 drw 19
Figure 3. Busy and chip enable routing for both width and depth
expansion with IDT7024 RAMs.
used by one processor to inhibit the other from accessing a portion of the
Dual-Port RAM or any other shared resource.
The Dual-Port RAM features a fast access time, and both ports are
completely independent of each other. This means that the activity on the
left port in no way slows the access time of the right port. Both ports are
identical in function to standard CMOS Static RAM and can be read from,
or written to, at the same time with the only possible conflict arising from the
simultaneous writing of, or a simultaneous READ/WRITE of, a nonsemaphore location. Semaphores are protected against such ambiguous
situations and may be used by the system program to avoid any conflicts
in the non-semaphore portion of the Dual-Port RAM. These devices have
an automatic power-down feature controlled by CE, the Dual-Port RAM
enable, and SEM, the semaphore enable. The CE and SEM pins control
on-chip power down circuitry that permits the respective port to go into
standby mode when not selected. This is the condition which is shown in
Truth Table I where CE and SEM = VIH.
Systems which can best use the IDT7024 contain multiple processors
or controllers and are typically very high-speed systems which are
software controlled or software intensive. These systems can benefit from
a performance increase offered by the IDT7024's hardware semaphores,
which provide a lockout mechanism without requiring complex programming.
Software handshaking between processors offers the maximum in
system flexibility by permitting shared resources to be allocated in varying
configurations. The IDT7024 does not use its semaphore flags to control
any resources through hardware, thus allowing the system designer total
flexibility in system architecture.
An advantage of using semaphores rather than the more common
methods of hardware arbitration is that wait states are never incurred
in either processor. This can prove to be a major advantage in very
high-speed systems.
How the Semaphore Flags Work
The semaphore logic is a set of eight latches which are independent
of the Dual-Port RAM. These latches can be used to pass a flag, or token,
from one port to the other to indicate that a shared resource is in use. The
semaphores provide a hardware assist for a use assignment method
called “Token Passing Allocation.” In this method, the state of a semaphore
latch is used as a token indicating that shared resource is in use. If the left
processor wants to use this resource, it requests the token by setting the
latch. This processor then verifies its success in setting the latch by reading
6.42
18
Feb.20.20
CE
MASTER
Dual Port
RAM
BUSY (L) BUSY (R)
DECODER
Military, Industrial and Commercial Temperature Ranges
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
it. If it was successful, it proceeds to assume control over the shared
resource. If it was not successful in setting the latch, it determines that the
right side processor has set the latch first, has the token and is using the
shared resource. The left processor can then either repeatedly request
that semaphore’s status or remove its request for that semaphore to perform
another task and occasionally attempt again to gain control of the token via
the set and test sequence. Once the right side has relinquished the token,
the left side should succeed in gaining control.
The semaphore flags are active LOW. A token is requested by writing
a zero into a semaphore latch and is released when the same side writes
a one to that latch.
The eight semaphore flags reside within the IDT7024 in a separate
memory space from the Dual-Port RAM. This address space is accessed
by placing a LOW input on the SEM pin (which acts as a chip select for the
semaphore flags) and using the other control pins (Address, OE, and
R/W) as they would be used in accessing a standard Static RAM. Each
of the flags has a unique address which can be accessed by either side
through address pins A0 – A2. When accessing the semaphores, none of
the other address pins has any effect.
When writing to a semaphore, only data pin D0 is used. If a low level
is written into an unused semaphore location, that flag will be set to a zero
on that side and a one on the other side (see Truth Table III). That
semaphore can now only be modified by the side showing the zero. When
a one is written into the same location from the same side, the flag will be
set to a one for both sides (unless a semaphore request from the other side
is pending) and then can be written to by both sides. The fact that the side
which is able to write a zero into a semaphore subsequently locks out writes
from the other side is what makes semaphore flags useful in interprocessor
communications. (A thorough discussion on the use of this feature follows
shortly.) A zero written into the same location from the other side will be
stored in the semaphore request latch for that side until the semaphore is
freed by the first side.
When a semaphore flag is read, its value is spread into all data bits so
that a flag that is a one reads as a one in all data bits and a flag containing
a zero reads as all zeros. The read value is latched into one side’s output
register when that side's semaphore select (SEM) and output enable (OE)
signals go active. This serves to disallow the semaphore from changing
state in the middle of a read cycle due to a write cycle from the other side.
Because of this latch, a repeated read of a semaphore in a test loop must
cause either signal (SEM or OE) to go inactive or the output will never
change.
A sequence WRITE/READ must be used by the semaphore in order
to guarantee that no system level contention will occur. A processor
requests access to shared resources by attempting to write a zero into a
semaphore location. If the semaphore is already in use, the semaphore
request latch will contain a zero, yet the semaphore flag will appear as one,
a fact which the processor will verify by the subsequent read (see Truth
Table III). As an example, assume a processor writes a zero to the left port
at a free semaphore location. On a subsequent read, the processor will
verify that it has written successfully to that location and will assume control
over the resource in question. Meanwhile, if a processor on the right side
attempts to write a zero to the same semaphore flag it will fail, as will be
verified by the fact that a one will be read from that semaphore on the right
side during subsequent read. Had a sequence of READ/WRITE been
used instead, system contention problems could have occurred during the
gap between the read and write cycles.
It is important to note that a failed semaphore request must be followed
by either repeated reads or by writing a one into the same location. The
reason for this is easily understood by looking at the simple logic diagram
of the semaphore flag in Figure 4. Two semaphore request latches feed
into a semaphore flag. Whichever latch is first to present a zero to the
semaphore flag will force its side of the semaphore flag LOW and the other
side HIGH. This condition will continue until a one is written to the same
semaphore request latch. Should the other side’s semaphore request latch
have been written to a zero in the meantime, the semaphore flag will flip
over to the other side as soon as a one is written into the first side’s request
latch. The second side’s flag will now stay LOW until its semaphore request
latch is written to a one. From this it is easy to understand that, if a semaphore
is requested and the processor which requested it no longer needs the
resource, the entire system can hang up until a one is written into that
semaphore request latch.
The critical case of semaphore timing is when both sides request
a single token by attempting to write a zero into it at the same time.
The semaphore logic is specially designed to resolve this problem.
If simultaneous requests are made, the logic guarantees that only one
side receives the token. If one side is earlier than the other in making the
request, the first side to make the request will receive the token. If both
requests arrive at the same time, the assignment will be arbitrarily made
to one port or the other.
One caution that should be noted when using semaphores is that
semaphores alone do not guarantee that access to a resource is secure.
As with any powerful programming technique, if semaphores are misused
or misinterpreted, a software error can easily happen.
Initialization of the semaphores is not automatic and must be handled
via the initialization program at power-up. Since any semaphore request
flag which contains a zero must be reset to a one, all semaphores on both
sides should have a one written into them at initialization from both sides
to assure that they will be free when needed.
Using Semaphores—Some Examples
Perhaps the simplest application of semaphores is their application as
resource markers for the IDT7024’s Dual-Port RAM. Say the 4K x 16 RAM
was to be divided into two 2K x 16 blocks which were to be dedicated at
any one time to servicing either the left or right port. Semaphore 0 could
be used to indicate the side which would control the lower section of
memory, and Semaphore 1 could be defined as the indicator for the upper
section of memory.
To take a resource, in this example the lower 2K of Dual-Port RAM,
the processor on the left port could write and then read a zero in to
Semaphore 0. If this task were successfully completed (a zero was read
back rather than a one), the left processor would assume control of the
lower 2K. Meanwhile the right processor was attempting to gain control of
the resource after the left processor, it would read back a one in response
to the zero it had attempted to write into Semaphore 0. At this point, the
software could choose to try and gain control of the second 2K section by
writing, then reading a zero into Semaphore 1. If it succeeded in gaining
control, it would lock out the left side.
Once the left side was finished with its task, it would write a one to
Semaphore 0 and may then try to gain access to Semaphore 1. If
Semaphore 1 was still occupied by the right side, the left side could undo
its semaphore request and perform other tasks until it was able to write, then
6.42
19
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
read a zero into Semaphore 1. If the right processor performs a similar task
with Semaphore 0, this protocol would allow the two processors to swap
2K blocks of Dual-Port RAM with each other.
The blocks do not have to be any particular size and can even be
variable, depending upon the complexity of the software using the
semaphore flags. All eight semaphores could be used to divide the DualPort RAM or other shared resources into eight parts. Semaphores can
even be assigned different meanings on different sides rather than being
given a common meaning as was shown in the example above.
Semaphores are a useful form of arbitration in systems like disk
interfaces where the CPU must be locked out of a section of memory during
a transfer and the I/O device cannot tolerate any wait states. With the use
of semaphores, once the two devices has determined which memory area
was “off-limits” to the CPU, both the CPU and the I/O devices could access
their assigned portions of memory continuously without any wait states.
Semaphores are also useful in applications where no memory “WAIT”
state is available on one or both sides. Once a semaphore handshake has
been performed, both processors can access their assigned RAM
segments at full speed.
Another application is in the area of complex data structures. In this
case, block arbitration is very important. For this application one processor
may be responsible for building and updating a data structure. The other
processor then reads and interprets that data structure. If the interpreting
processor reads an incomplete data structure, a major error condition may
exist. Therefore, some sort of arbitration must be used between the two
different processors. The building processor arbitrates for the block, locks
it and then is able to go in and update the data structure. When the update
is completed, the data structure block is released. This allows the
interpreting processor to come back and read the complete data structure,
thereby guaranteeing a consistent data structure.
L PORT
R PORT
SEMAPHORE
REQUEST FLIP FLOP
D0
D
SEMAPHORE
REQUEST FLIP FLOP
Q
Q
WRITE
D
D0
WRITE
SEMAPHORE
READ
SEMAPHORE
READ
,
2740 drw 20
Figure 4. IDT7024 Semaphore Logic
6.42
20
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Ordering Information
XXXXX
A
999
A
Device
Type
Power
Speed
Package
A
A
A
Process/
Temperature
Range
Blank
8
Tube or Tray
Tape & Reel
Blank
I(1)
B
Commercial (0°C to +70°C)
Industrial (-40°C to +85°C)
Military (-55°C to +125°C)
Compliant to MIL-PRF-38535 QML
G(2)
Green
PF
G
J
F
100-pin TQFP (PN100, PNG100)
84-pin PGA (GU84)
84-pin PLCC (PL84 / PLG84)
84-pin Flatpack (FP84)
15
17
20
25
35
55
70
Commercial Only
Commercial Only
Commercial, Industrial & Military
Commercial & Military
Commercial & Military
Commercial & Military
Military Only
S
L
Standard Power
Low Power
7024
64K (4K x 16) Dual-Port RAM
Speed in
nanoseconds
2740 drw 21
NOTE:
1. Industrial temperature range is available on selected PLCC packages in low power. For other speeds, packages and powers contact your sales office.
2. Green parts available. For specific speeds, packages and powers contact your local sales office.
LEAD FINISH (SnPb) parts are Obsolete excluding PGA & Flatpack. Product Discontinuation Notice - PDN# SP-17-02
Note that information regarding recently obsoleted parts are included in this datasheet for customer convenience.
Orderable Part Information
Speed
(ns)
15
Pkg.
Code
Pkg.
Type
Temp.
Grade
7024L15JG
PLG84
PLCC
C
17
7024L15JG8
PLG84
PLCC
C
20
C
25
Orderable Part ID
7024L15PFG
7024L15PFG8
PNG100
TQFP
Speed
(ns)
Pkg.
Code
Pkg.
Type
Temp.
Grade
7024S17G
GU84
PGA
C
7024S20G
GU84
PGA
C
7024S25G
GU84
PGA
C
7024S25GB
GU84
PGA
M
M
Orderable Part ID
PNG100
TQFP
C
17
7024L17G
GU84
PGA
C
7024S35FB
FP84
FPACK
20
7024L20FB
FP84
FPACK
M
7024S35G
GU84
PGA
C
7024L20G
GU84
PGA
C
7024S35GB
GU84
PGA
M
7024L20GB
GU84
PGA
M
7024S55FB
FP84
FPACK
M
I
7024S55G
GU84
PGA
C
7024S55GB
GU84
PGA
M
7024S70FB
FP84
FPACK
M
7024S70GB
GU84
PGA
M
7024L20JGI
PLG84
PLCC
7024L20JGI8
PLG84
PLCC
I
7024L20PFGI
PNG100
TQFP
I
7024L20PFGI8
PNG100
TQFP
I
PGA
C
M
25
7024L25G
GU84
7024L25GB
GU84
PGA
35
7024L35FB
FP84
FPACK
M
7024L35G
GU84
PGA
C
55
70
7024L35GB
GU84
PGA
M
7024L55G
GU84
PGA
C
7024L55GB
GU84
PGA
M
7024L70GB
GU84
PGA
M
35
55
70
6.42
21
Feb.20.20
7024S/L
High-Speed 4K x 16 Dual-Port Static RAM
Military, Industrial and Commercial Temperature Ranges
Datasheet Document History
01/13/99:
06/04/99:
04/04/00:
05/19/00:
09/12/01:
07/25/05:
10/29/08:
06/11/13:
05/23/18:
12/05/19:
02/20/20:
Initiated datasheet document history
Converted to new format
Cosmetic and typographical corrections
Pages 2 and 3 Added additional notes to pin configurations
Changed drawing format
Page 1 Corrected DSC number
Replaced IDT logo
Page 6 Corrected typo in Data Retention chart
Changed ±500mV to 0mV in notes
Page 3 Clarified TA parameter
Page 4 Increased storage temperature parameter
Pages 5 and 6 DC Electrical parameters–changed wording from "open" to "disabled"
Page 2 & 3 Added date revision for pin configurations
Page 5 Added Industrial temp to the column heading for 20ns to DC Electrical Characteristics
Pages 8,10,13&15 Added Industrial temp to the column headings for 20ns to AC Electrical Characteristics
Pages 3,5,6,8,10,13&15 Removed Industrial temp note from all tables footnotes
Page 21 Added Industrial to 20ns ordering information
Page 1 Added green availability to features
Page 21 Added green indicator to ordering information
Page 1 & 21 Replaced old IDT ® logo with the new IDTTM logo
Page 21 Updated address and phone contact information
Page 21 Removed "IDT" from orderable part number
Page 21 Ordering Information. Added T&R
Product Discontinuation Notice - PDN# SP-17-02
Last time buy expires June 15, 2018
Pages 1 & 21 Deleted obsolete Industrial 55ns speed grade and added Industrial 20ns speed grade
Pages 2 & 3 Rotated PLG84 PLCC, FP84 Flatpack and PNG100 TQFP pin configurations to accurately reflect pin 1
orientation
Page 21 Added Orderable Part Information tables
Pages 1 - 23 Rebranded as Renesas datasheet
6.42
22
Feb.20.20
IMPORTANT NOTICE AND DISCLAIMER
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(Rev.1.0 Mar 2020)
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