ETC IDT7381L25J

IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
16-BIT CMOS
CASCADABLE ALU
FEATURES:
−
−
−
−
−
−
−
−
−
−
−
−
−
IDT7381
DESCRIPTION:
High-performance 16-bit Arithmetic Logic Unit (ALU)
25ns to 55ns clocked ALU operations
Ideal for radar, sonar or image processing applications
74S381 instruction set (8 functions)
Replaces Gould S614381 or Logic Devices L4C381
Cascadable with or without carry look-ahead
Pipeline or flow-through modes
Internal feedback path for accumulation
Three-state outputs
TTL-compatible
Produced with advanced submicron CMOS technology
Available in PLCC
Speeds available: L/25/30/40/55
The IDT7381 is a high-speed cascadable Arithmetic Logic Unit (ALU).
These three-bus devices have two input registers, an ultra-fast 16-bit ALU
and 16-bit output register. With IDT’s high-performance CMOS technology,
the IDT7381 can do arithmetic or logic operations in 25ns. The IDT7381
functionally replaces four 54/74S381 four-bit ALUs in a 68-pin package.
The two input operands, A and B, can be clocked or fed through for
flexible pipelining. The F output can also be set into clocked or flow-through
mode. An output enable is provided for three-state control of the output port
on a bus.
The IDT7381 has three function pins to select 1 of 8 arithmetic or logic
operations. The two R and S selection pins determine whether A, B, F or
0 are fed into the ALU. This ALU has carry-out, propagate and generate
outputs for cascading using carry look-ahead.
FUNCTIONAL BLOCK DIAGRAM
A0
B0
-1 5
-1 5
16
ENA
16
A R EG
B R EG
A MUX
CL K
ENB
B MUX
0000 H
FT AB
0000 H
S MUX
R MUX
RS 0
-1
2
P
G
C1 6
OVF
Z
I
16-BIT ALU
C0
EN F
FTF
0-2
3
F RE G
F M UX
PO W E R
SU P P LY
OE
GND
VCC
16
F0
- 15
COMMERCIAL TEMPERATURE RANGE
APRIL 2001
1
c
2001
Integrated Device Technology, Inc.
DSC-2525/-
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
B8
B9
B 10
B 11
B 12
A9
9
10
2
A10
11
A11
12
1 68 67 66 65 64 63 62 61
60
Pin 1
59
Desig nato r
58
A12
13
57
B4
A13
14
56
B3
A14
15
55
B2
A15
16
54
B1
CL K
17
53
B0
VCC
18
52
ENA
GND
19
51
ENB
C 16
20
50
FT AB
P
21
49
RS 1
G
22
48
RS 0
Z
23
47
I
2
O VF
24
46
I
1
EN F
25
45
I
0
FTF
26
44
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
PLCC
TOP VIEW
2
F1
F2
F3
F4
F5
F6
F7
F8
F9
F 10
F 11
F 12
F 13
F 14
F 15
OE
J68 - 1
F0
3
B 13
4
B 14
A3
5
B 15
A4
6
A0
A5
7
A1
A6
8
A2
A7
A8
PIN CONFIGURATION
B7
B6
B5
C0
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
PIN DESCRIPTION
Pin Name
I/O
Description
A0 - A15
I
Sixteen–bit data input port.
B0 - B15
I
Sixteen–bit data input port.
ENA
I
Register enable for the A input port; active low pin.
ENB
I
Register enable for the B input port; active low pin.
FTAB
I
Flow–through control pin. When this pin is high, both register A and B are transparent.
F0 – F15
O
Sixteen–bit data output port.
ENF
I
Register enable for the F output port; active low pin.
FTF
I
Flow–through control pin. When this pin is high, the F register is transparent.
CLK
I
Clock input.
OE
I
Output enable control pin. When this pin is high, the output port F is in a high impedance state. When low, the output
port F is active.
C0
I
Carry input. This pin receives arithmetic carries from less significant ALU components in a cascade
configuration.
C16
O
Carry output. This pin produces arithmetic carries to more significant ALU components in a cascaded
configuration.
OVF
O
This pin indicates a two’s complement arithmetic overflow, when high.
Z
O
This pin indicates a zero output result, when high.
RS0 – RS1
I
Two control pins used to select input operands for the R and S multiplexers.
I0 - I2
I
Three control pins to select the ALU function performed.
P
O
Indicates the carry propagate output state to the ALU.
G
O
Indicates the carry generate output state to the ALU.
VCC
Power supply pin, 5V.
GND
Ground pin, 0V.
R AND S MUX TABLE
ALU FUNCTION TABLE
RS1
RS0
R Mux
S Mux
I2
I1
I0
0
0
A
F
0
0
0
F=0
0
1
A
0
0
0
1
F = R + S + C0
1
0
0
B
0
1
0
F = R + S + C0
1
1
A
B
0
1
1
F = R + S + C0
1
0
0
F = R xor S
1
0
1
F = R or S
1
1
0
F = R and S
1
1
1
F = all 1’s
3
Function
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
ABSOLUTE MAXIMUM RATINGS(1)
Symbol
Description
CAPACITANCE (TA = +25°C, f = 1.0MHz)
Max.
Unit
Symbol
Parameter(1)
Conditions
Pkg.
Typ.
Unit
CIN
Input Capacitance
VIN = 0V
PGA
10
pF
PLCC
5
PGA
12
PLCC
7
VTERM
Terminal Voltage with
Respect to Ground
–0.5 to
VCC + 0.5
V
VCC
Power Supply Voltage
–0.5 to +7.0
V
TSTG
Storage Temperature
–55 to +125
°C
IOUT
DC Output Current
50
mA
C OUT
Output Capacitance
VOUT = 0V
pF
NOTE:
1. This parameter is sampled at initial characterization and is not production
tested.
NOTE:
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. Under no circumstances should an input
of an I/O Pin be greater than VCC + 0.5V.
DC ELECTRICAL CHARACTERISTICS
Commercial: TA = 0°C to +70°C, VCC = 5.0V ± 5%
Symbol
Test Conditions(1)
Parameter
Min.
Typ.(2)
Max.
Unit
2
—
—
V
VIH
Input HIGH Level
Guaranteed Logic HIGH Level
VIL
Input LOW Level
Guaranteed Logic LOW Level
—
—
0.8
V
IIH
Input HIGH Current
VCC = Max., VIN = 2.7V
—
—
10
µA
IIL
Input LOW Current
VCC = Max., VIN = 0.5V
—
—
–10
µA
IOS(3)
Short Circuit Current
VCC = Max., VOUT = GND
IOZ
Off State (High Impedance)
VCC = Max.
Output Current
VOH
Output HIGH Voltage
VCC = Min.
VOL
Output LOW Voltage
VCC = Min.
–20
—
–100
mA
VO = 0.5V
—
–0.1
–20
µA
VO = 2.7V
—
–0.1
20
IOH = –4mA
2.4
—
—
V
IOL = 8mA
—
—
0.5
V
VIN = VIH or VIL
VIN = VIH or VIL
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at VCC = 5.0V, +25°C ambient and maximum loading.
3. Not more than one output should be shorted at one time. Duration of the short circuit test should not exceed one second.
4
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Commercial: TA = 0°C to +70°C, VCC = 5.0V ± 5%
Symbol
Test Conditions(1)
Parameter
Min.
Typ.(2)
Max.
Unit
ICC
Quiescent Power Supply Current
VCC = Max.
VIN =GND or VCC
—
2
6
mA
∆ICC(3)
Quiescent Power Supply Current
TTL Input HIGH
VCC = Max.
VIN = 3.4V
—
0.5
1
mA/
input
ICCD(4)
Dynamic Power Supply Current
VCC = Max.
Outputs disabled
VIN = GND or VCC
Mode: FTAB = FTF = 1
—
15
48
µA/
MHz
ICCD1
Dynamic Power Supply Current
VCC = Max.
Outputs Disabled
All Data Inputs Disabled
fi = 10MHz, fCP = 10MHz
50% Duty Cycle
VIL = GND, VIH = VCC
Mode: FTAB = FTF = 1
—
20
33
mA
ICCD2(6)
Dynamic Power Supply Current
VCC = Max.
Outputs Enabled. (CL = 50pF)
All Data Inputs Sw itching
fi = 10MHz, fCP = 10MHz
—
40
60
mA
Outputs Disabled
—
22
39
mA
Outputs Enabled
—
42
76
mA
50% Duty Cycle
VIL = GND, VIH = VCC
Mode: FTAB = FTF = 1
IC(7)
Total Power Supply Current
VCC = Max.
VIN = GND or VCC
All Data Inputs Switching
fi = 10MHz, fCP = 10MHz
50% Duty Cycle
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at VCC = 5.0V, +25°C ambient.
3. Per TTL driven input (VIN = 3.4V); all other inputs at VCC or GND.
4. This parameter is not directly testable, but is derived from ICCD1 for use in Total Power Supply calculations.
5. Total power supply current is calculated as follows:
IC = IQUIESCENT + IINPUTS + IDYNAMIC
IC = ICC + ∆ICC DHNT + ICCD (fCP + fiNi)
ICC = Quiescent Current
∆ICC = Power Supply Current for a TTL High Input (VIN = 3.4V)
DH = Duty Cycle for TTL Inputs High
NT = Number of TTL Inputs at DH
ICCD = Dynamic Current Caused by an Output Transition Pair (HLH or LHL)
fCP = Clock Frequency for Register Devices (Zero for Non-Register Devices)
fi = Input Frequency
Ni = Number of Inputs at fi
All currents are in milliamps and all frequencies are in megahertz.
6. This parameter is not production tested but is an indicator of the power dissipated with outputs loaded.
7. Values for these conditions are examples of the IC formula in note 5 above. These are guaranteed but not tested.
5
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
AC ELECTRICAL CHARACTERISTICS
(VCC = 5V ± 5%, TA = 0°C to +70°C)
Maximum Combinational Propagation Delays
IDT7381L25
From Input
Z,OVF
IDT7381L30
F0–15
P, G, N
C16
F0–15
P, G, N
CLK
13
22
C0
—
—
I0–2, RS0, RS1
—
22
22
CLK
27
22
26
C0
22
—
16
I0–2, RS0, RS1
22
22
22
22
A0–A15, B0–B15
—
18
25
CLK
13
—
—
C0
—
—
I0–2, RS0, RS1
—
22
A0–A15, B0–B15
26
C0
I0–2, RS0, RS1
Z,OVF
C16
Unit
26
22
20
28
30
28
ns
16
16
—
—
20
20
ns
22
—
28
28
28
ns
22
33
28
30
28
ns
16
28
—
20
20
ns
28
28
28
28
ns
22
—
24
30
28
ns
—
19
—
—
—
ns
16
16
—
—
20
20
ns
22
22
—
28
28
28
ns
18
25
22
32
24
30
28
ns
22
—
16
16
28
—
20
20
ns
22
22
22
22
28
28
28
28
ns
FTAB = 0, FTF = 0
FTAB = 0, FTF = 1
FTAB = 1, FTF = 0
FTAB = 1, FTF = 1
Maximum Combinational Propagation Delays
IDT7381L40
From Input
IDT7381L55
F0–15
P, G, N
Z,OVF
C16
F0–15
P, G, N
Z,OVF
C16
Unit
CLK
26
30
44
32
32
38
53
36
ns
C0
—
—
28
20
—
—
34
22
ns
I0–2, RS0, RS1
—
32
34
35
—
42
42
42
ns
CLK
46
30
44
32
56
38
53
36
ns
C0
30
—
28
20
37
—
34
22
ns
I0–2, RS0, RS1
40
32
34
35
55
42
42
42
ns
A0–A15, B0–B15
—
30
40
32
—
36
46
37
ns
CLK
26
—
—
—
32
—
—
—
ns
C0
—
—
28
20
—
—
34
22
ns
I0–2, RS0, RS1
—
32
34
35
—
42
42
42
ns
A0–A15, B0–B15
40
30
40
32
55
36
46
37
ns
C0
30
—
28
20
37
—
34
22
ns
I0–2, RS0, RS1
40
32
34
35
55
42
42
42
ns
FTAB = 0, FTF = 0
FTAB = 0, FTF = 1
FTAB = 1, FTF = 0
FTAB = 1, FTF = 1
NOTES:
1. Only for FTF = 0.
2. Minimum propagation delays are not production tested but guaranteed to be greater than or equal to 3ns.
6
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
AC ELECTRICAL CHARACTERISTICS
(VCC = 5V ± 5%, TA = 0°C to +70°C) - (Cont'd.)
Minimum Set-up and Hold Times Relative to Clock (CLK)
IDT7381L25
Input
IDT7381L30
IDT7381L40
IDT7381L55
Set-up
Hold
Set-up
Hold
Set-up
Hold
Set-up
Hold
Unit
A0–A15, B0–B15
6
0
6
0
6
0
8
0
ns
C0 (1)
16
0
16
0
16
0
21
0
ns
I0–2, RS0, RS1 (1)
24
0
29
0
32
0
44
0
ns
ENA, ENB, ENF
6
0
6
0
6
0
8
0
ns
A0–A15, B0–B15
16
0
25
0
28
0
35
0
ns
C0
16
0
16
0
16
0
21
0
ns
I0–2, RS0, RS1
24
0
29
0
32
0
44
0
ns
ENF
6
0
6
0
6
0
8
0
ns
FTAB = 0, FTF = X
FTAB = 1, FTF = 0
Minimum Clock Cycle Times and Pulse Widths
Parameter
IDT7381L25
IDT7381L30
IDT7381L40
IDT7381L55
Unit
Clock LOW Time
6
8
10
14
ns
Clock HIGH Time
6
8
10
14
ns
Clock Period
20
25
34
43
ns
IDT7381L25
IDT7381L30
IDT7381L40
IDT7381L55
Unit
Enable Time
10
15
18
20
ns
Disable Time
10
15
18
20
ns
Maximum Output Enable/Disable Times
Parameter
NOTES:
1. Only for FTF = 0.
2. Minimum propagation delays are not production tested but guaranteed to be greater than or equal to 3ns.
7
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
WAVEFORMS FOR FTAB = 0, FTF = X
T1
T2
CLK
Set-up
Hold
A 0- 15
DATA 1
DATA 2
DATA 3
B 0- 15
Set-up
DATA 1
C0
Hold
DATA 3
DATA 2
Set-up
Hold
I 0- 2 ,
DATA 1
DATA 2
RS 0- 1
Set-up
ENA, ENB
ENF
DATA 1
DATA 3
Hold
DATA 2
DATA 3
OE
Prop. 1
Disable
Enable
F 0- 15
Result
(FTF = 0)
Prop. 3
Prop. 2
Prop. 1
Disable
Enable
F 0- 15
Result
(FTF = 1)
Prop. 2
Prop. 1
P, G
Result
Prop. 2
Prop. 3
Prop. 1
Result
Z, OVF
Prop. 2
Prop. 3
Prop. 1
C 16
Result
Prop. 1: Propagation delay with respect to the CLK.
Prop. 2: Propagation delay with respect to I 0- 2 , RS 0- 2.
Prop. 3: Propagation delay with respect to C0.
8
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
WAVEFORMS FOR FTAB = 1, FTF = X
T1
T2
CLK
(FTF = 0)
Set-up
Hold
A 0- 15
DATA 1
DATA 2
DATA 3
B 0- 15
Set-up
DATA 1
C0
Hold
DATA 2
Set-up
DATA 3
Hold
I0- 2 ,
DATA 1
DATA 2
DATA 3
RS 0- 1
Set-up
DATA 2
DATA 1
ENF
Hold
DATA 3
OE
Prop. 1
Disable
Enable
F 0- 15
Result
(FTF = 0)
Prop. 4
Prop. 3
Prop. 2
Disable
Enable
F 0- 15
Result
(FTF = 1)
Prop. 4 (for FTF = 1 only)
Prop. 2
Result
P, G
Prop. 2
Prop. 4 (For FTF = 1 only)
Prop. 3
Result
Z, OVF
Prop. 4 (For FTF = 1 only)
Prop. 3
Prop. 2
C 16
Prop.
Prop.
Prop.
Prop.
1:
2:
3:
4:
Result
Propagation
Propagation
Propagation
Propagation
delay
delay
delay
delay
with
with
with
with
respect
respect
respect
respect
to
to
to
to
the CLK.
I0- 2 , RS 0- 2.
C0.
A, B.
9
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
PROPAGATION DELAY CALCULATIONS FOR TWO IDT7381S
To Output
From Input
To Set PUT Time
Flags (1)
F0 – 15
Relative to Clock (CLK)
FTAB = 0, FTF = 0
CLK
C0
I0 – 2, RS0 – 1
A0 – 15, B0 – 15
ENA, ENB,ENF
As in 16-bit case
....
....
....
....
(Clk → C16) + (C0 → flag)
(C0 → C16) + (C0 → flag)
(I0–2, RS0–1 → C16) + (C0 → flag)
....
....
....
(C0 → C16) + (C0 set–up time)
(I0–2, RS0–1 → C16) + (C0 set–up time)
As in 16-bit case
As in 16-bit case
FTAB = 0, FTF = 1
CLK
C0
I0 – 2, RS0 – 1
A0 – 15, B0 – 15
ENA, ENB,ENF
(Clk → C16) + (C0 → F0–15)
(C0 → C16) + (C0 → F0–15)
(I0–2, RS0–1 → C16) + (C0 → F0–15)
....
....
(Clk → C16) + (C0 → flag)
(C0 → C16) + (C0 → flag)
(I0–2, RS0–1 → C16) + (C0 → flag)
....
....
....
(C0 → C16) + (C0 set–up time)
(I0–2, RS0–1 → C16) + (C0 set–up time)
As in 16-bit case
As in 16-bit case
FTAB = 1, FTF = 0
CLK
C0
I0 – 2, RS0 – 1
A0 – 15, B0 – 15
ENA, ENB,ENF
As in 16-bit case
....
....
....
....
....
(C0 → C16) + (C0 → flag)
(I0–2, RS0–1 → C16) + (C0 → flag)
(A0–15, B0–15 → C16) + (C0 → flag)
....
....
(C0 → C16) + (C0 set–up time)
(I0–2, RS0–1 → C16) + (C0 set–up time)
As in 16-bit case
As in 16-bit case
FTAB = 0, FTF = 1
CLK
C0
I0 – 2, RS0 – 1
A0 – 15, B0 – 15
ENA, ENB,ENF
Don't care condition
(C0 → C16) + (C0 → F0–15)
(I0–2, RS0–1 → C16) + (C0 → F0–15)
(A0–15, B0–15 → C16) + (C0 → F0–15)
....
Don't care condition
(C0 → C16) + (C0 → flag)
(I0–2, RS0–1 → C16) + (C0 → flag)
(A0–15, B0–15 → C16) + (C0 → flag)
....
....
....
....
....
....
NOTE:
1. Flags are P, G, OVF, Z and C16.
10
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
CASCADING THE IDT7381
Some applications require 32-bit or wider input operands. Cascading
is the hardware solution. It provides a high speed alternative in handling
more than 16-bit wide operands.
1. Cascading the IDT7381
Cascading to 32-bit wide operands takes only two IDT7381s and no
external hardware. However, cascading to data widths greater than 32bit can be done in two ways: without external hardware (slow method) or
by using a carry look ahead generator.
a) Cascading the IDT7381 without a carry-look-ahead generator:
(Figures 1 and 2)
1. Connect the C16 output of the least significant device into the C0
input of the next most significant device.
2. Common lines to all devices are: RS 0–1, I0–2, Clk, FTF, FTAB,
ENA, ENB, ENF.
3. Take OVF, C16, P, G of the most significant device as valid.
4. The system’s zero flag (Z) is obtained by ANDing all zero flag
results.
b) Cascading three or more IDT7381s with carry-look-ahead (CLA)
generator: (Figure 3)
1. Connect the P and G outputs of each device to the CLA generator’s
corresponding inputs.
2. Take the CLA generator outputs into the C0 inputs of each device
(except for the least significant one).
3. Common lines to all devices are: RS 0–1, I0–2, Clk, FTF, FTAB,
ENA, ENB, ENF.
4. Take OVF, C16, P, G of the most significant device as valid.
5. Carry-in to the system should be connected to the C0 input of the
least significant device and also to the CLA generator.
2. Time Delay Considerations
Once cascading has taken place, time delays may become critical in high
performance systems. Our main interest here is focused on “propagation
delays”, i.e. calculating the time required for an input signal to propagate
through several cascaded devices up to a specific output in another device
within the cascaded system.
11
Propagation Delay
The propagation delay for two devices between the input and output of
interest (input to output delay) is done as follows:
1. Calculate delay between the input and C16 in the first device.
2. Calculate delay between C0 and the output in the second device.
3. Add both results.
The following table is an example on how to build a propagation delay
table for all inputs in a 32-bit IDT7381 cascaded system.
Propagation delay calculations can be extended to n–cascaded devices
as the sum of the delays in all devices between the input and output of interest.
That is:
(Input)1 → (C16)1 = t1
...
(C0)i → (C16)i = ti
(C0)i + 1 → (C16)i + 1 = ti + 1
...
(C0)n → (Output)n = tn
Where the subscript i denotes the device number and the arrow (→)
represents the delay in between. Notice that i + 1 is the immediate upper
device from device i. Adding the delays ti we get:
Propagation delay = t1 + t2 + ... + ti + ti + 1 + ... + tn
Total Delay
As seen from Figure 8, the propagation delay is within the IDT7381
devices only. A complete analysis should also include the delay associated
with the transmission line Li (which depends on the line length and its
impedance). This line delay should then be added to the propagation delay
to obtain the total delay for the cascaded system:
Total delay = Propagation delay + Transmission line delay
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
A 16 - 31
G
B 16 - 31
A 0 - 15
B 0 - 15
11 RS 0 - 1
ID T7381
ID T7381
P
Clk, I
0 -2
, ENA, ENB
ENF, FTF, FTAB
C 16
MSD
C 16
C0
LSD
Z
F 16 - 3 1
F 0 - 15
C0
OVF
Z
Z
C IN
Figure 1. Cascading Two IDT7381s to 32 Bits
A 32 - 47
G
B 32 - 47
A 16 - 31
A 0 - 15
ID T7381
ID T73 81
P
B 16 - 31
B 0 - 15
11
ID T7381
C 16
OVF
Z
C 16
C0
Z
MSD
C 16
C0
LS D
Z
C0
Z
F 32 - 4 7
F 16 - 3 1
RS0 -1
C lk, I 0 - 2 ,
EN A, EN B
EN F, FTF,
FTA B
C IN
F 0 - 15
Figure 2. Cascading Three IDT7381s to 48 Bits Wide
without a Carry-lookahead Generator
A 32
G
B 32
- 47
- 47
A 16
B 16
A 0 - 15
- 31
ID T7381
ID T7381
P
- 31
B 0 - 15
11
ID T7381
C 16
OVF
P
G
Z
Z
C0
C0
LS D
MSD
F 32
F 16
-4 7
C n+y
EN A, EN B
EN F, FTF,
FTA B
P
G
Z
C0
Z
RS0 -1
C lk, I 0 - 2 ,
F 0 - 15
-3 1
P1 G1
C n+x
FC T182/A Looka he ad G ene rator
P0 G0
Cn
Figure 3. Cascading Three IDT7381s to 48 Bits Wide
with a Carry-lookahead Generator
12
C IN
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
B 16 - 31
16
A 16 - 31
16
A M ux
B M ux
R M ux
B Reg
A Reg
B Reg
A Reg
B 0 - 15
16
A 0 - 15
16
A M ux
S M ux
B M ux
R M ux
16-Bit ALU
CLK
S M ux
16-Bit ALU
C
C 16
0
M SD
LSD
F Reg
F Reg
F M ux
F M ux
16
16
F 0 - 15
F 16 - 3 1
Figure 4. 32-Bit Configuration for FTAB = 0, FTF = 0
B 16 - 31
A 16 - 31
16
16
B Reg
A Reg
A M ux
B Reg
A Reg
B M ux
R M ux
B 0 - 15
16
A 0 - 15
16
A M ux
S M ux
S M ux
R M ux
16-Bit ALU
M SD
B M ux
16-Bit ALU
C
C 16
0
F M ux
LSD
F M ux
16
16
F 16 - 3 1
F 0 - 15
Figure 5. 32-Bit Configuration for FTAB = 0, FTF = 1
13
CLK
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
A 16 - 31
16
A 0 - 15
16
B 16 - 31
16
B 0 - 15
16
CLK
A M ux
B M ux
R M ux
A M ux
S M ux
B M ux
R M ux
16-Bit ALU
S M ux
16-Bit ALU
C
C 16
0
M SD
LSD
F Reg
F Reg
F M ux
F M ux
16
16
F 0 - 15
F 16 - 3 1
Figure 6. 32-Bit Configuration for FTAB = 1, FTF = 0
A 16 - 31
B 16 - 31
16
A 0 - 15
16
A M ux
B M ux
R M ux
B 0 - 15
16
16
A M ux
B M ux
S M ux
R M ux
C
C 16
16-Bit ALU
S M ux
16-Bit ALU
0
M SD
LSD
F M ux
F M ux
16
16
F 16 - 3 1
F 0 - 15
Figure 7. 32-Bit Configuration for FTAB = 1, FTF = 1
14
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
D0
L1
D1
L2
In
Dn
— t1 —
OU TPUT
— t2 —
— tn —
Figure 8. Propagation Delay = t1 + t2 + . . . + tn N-Cascaded Devices
AC TEST CONDITIONS
Input Rise levels
GND to 3V
Input Rise/Fall Times
3ns
Input Timing Reference Levels
1.5V
Output Reference Levels
1.5V
Output Load
Figure 1
15
IN PUT
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
TEST WAVEFORMS
TEST CIRCUITS FOR ALL OUTPUTS
SWITCH POSITION
Test
Open Drain
V CC
7.0V
Disable Low
All Other Tests
V OUT
V IN
50pF
T
C
500 Ω
L
SET-UP, HOLD, AND RELEASE TIMES
DATA
INPUT
tH
t SU
TIM ING
INPUT
ASYNCHRONOUS CONTROL
PRES ET
CLEA R
ETC.
SYNCHRONOUS CONTROL
PRES ET
CLEA R
CLOCK ENABLE
ETC.
t REM
t SU
Open
DEFINITIONS:
CL= Load capacitance: includes jig and probe capacitance.
RT = Termination resistance: should be equal to ZOUT of the Pulse
Generator.
D.U.T.
R
Closed
Enable Low
500 Ω
Pulse
Generator
Switch
3V
1.5V
0V
3V
1.5V
0V
PULSE WIDTH
LOW -HIGH-LOW
PULS E
1.5V
tW
3V
1.5V
0V
HIGH-LOW -HIGH
PULS E
1.5V
3V
1.5V
0V
tH
ENABLE AND DISABLE TIMES
PROPAGATION DELAY
ENAB LE
3V
1.5V
SAM E PHA SE
INPUT TRANSITION
t PLH
t PHL
OUTPUT
t PLH
OPPOS ITE PHASE
INPUT TRANSITION
t PHL
DISABLE
3V
CONTROL
INPUT
0V
1.5V
OUTPUT
NORMA LLY
LOW
3V
SW ITCH
CLOSE D
3.5V
1.5V
OUTPUT
NORMA LLY
HIGH
SW ITCH
OPEN
3.5V
0.3V
t PZH
1.5V
0V
0V
t PLZ
t PZL
V OH
1.5V
V OL
V OL
t PHZ
0.3V
V OH
1.5V
0V
0V
NOTES:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH
2. Pulse Generator for All Pulses: Rate ≤ 1.0MHz; tF ≤ 2.5ns; tR ≤ 2.5ns
16
IDT7381
16-BIT CASCADABLE ALU
COMMERCIAL TEMPERATURE RANGE
ORDERING INFORMATION
IDT
XXXX
Device Type
XX
Speed
X
Package
CORPORATE HEADQUARTERS
2975 Stender Way
Santa Clara, CA 95054
J
Plastic Leaded Chip C arrier (J68-1)
25
30
40
55
Speed Grade
7381L
16-Bit ALU
for SALES:
800-345-7015 or 408-727-6116
fax: 408-492-8674
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17