LOGIC LSH32JC20

LSH32
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
32-bit Cascadable Barrel Shifter
DEVICES INCORPORATED
FEATURES
DESCRIPTION
❑ 32-bit Input, 32-bit Output Multiplexed to 16 Lines
❑ Full 0-31 Position Barrel Shift
Capability
❑ Integral Priority Encoder for 32-bit
Floating Point Normalization
❑ Sign-Magnitude or Two’s Complement Mantissa Representation
❑ 32-bit Linear Shifts with Sign or
Zero Fill
❑ Independent Priority Encoder
Outputs for Block Floating Point
❑ 68-pin PLCC, J-Lead
The LSH32 is a 32-bit high speed
shifter designed for use in floating
point normalization, word pack/
unpack, field extraction, and similar
applications. It has 32 data inputs,
and 16 output lines. Any shift
configuration of the 32 inputs, including circular (barrel) shifting, left shifts
with zero fill, and right shift with sign
extend are possible. In addition, a
built-in priority encoder is provided
to aid floating point normalization.
SHIFT ARRAY
The 32 inputs to the LSH32 are
applied to a 32-bit shift array. The 32
outputs of this array are multiplexed
down to 16 lines for presentation at
the device outputs. The array may be
LSH32 BLOCK DIAGRAM
32
32
2:1
5
32-bit
BARREL
SHIFT
ARRAY
SI 4 -SI 0
RIGHT/LEFT
FILL/WRAP
16
16
NORM
In fill mode, as in wrap mode, the shift
code input represents the number of
shift positions directly for left shifts,
but the two’s complement of the shift
code results in the equivalent right
shift. However, for fill mode the R/L
input can be viewed as the most
2:1
5
SO 4 -SO 0
Essentially the LSH32 is configured as
a left shift device. That is, a shift code
of 000002 results in no shift of the
input field. A code of 000012 provides
an effective left shift of 1 position, etc.
When viewed as a right shift, the shift
code corresponds to the two’s complement of the shift distance, i.e., a
shift code of 111112 (–110) results in a
right shift of one position, etc.
When not in the wrap mode, the
LSH32 fills bit positions for which
there is no corresponding input bit.
The fill value and the positions filled
depend on the RIGHT/LEFT (R/L)
direction pin. This pin is a don’t care
input when in wrap mode. For left
shifts in fill mode, lower bits are filled
with zero as shown in Table 2. For
right shifts, however, the SIGN input
is used as the fill value. Table 3
depicts the bits to be filled as a
function of shift code for the right shift
case. Note that the R/L input changes
only the fill convention, and does not
affect the definition of the shift code.
SIGN I 31 -I 0
32:5
PRIORITY
ENCODE
configured such that any contiguous
16-bit field (including wraparound of
the 32 inputs) may be presented to the
output pins under control of the shift
code field (wrap mode). Alternatively, the wrap feature may be
disabled, resulting in zero or sign bit
fill, as appropriate (fill mode). The
shift code control assignments and the
resulting input to output mapping for
the wrap mode are shown in Table 1.
16
OE
Y 15 -Y 0
MS/LS
Special Arithmetic Functions
1
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
TABLE 1. WRAP MODE SHIFT CODE DEFINITIONS
Shift Code
Y 31
Y 30
Y 29
•••
Y 16
Y 15
•••
Y2
Y1
Y0
00000
00001
00010
00011
I31
I30
I29
I28
I30
I29
I28
I27
I29
I28
I27
I26
•••
I15
I14
I13
I12
•••
•••
I16
I15
I14
I13
•••
I2
I1
I0
I31
I1
I0
I31
I30
I0
I31
I30
I29
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•••
•••
•••
•••
OUTPUT MULTIPLEXER
•
•
•
•
•••
•
•
•••
•
•
•
01111
10000
10001
10010
I16
I15
I14
I13
I15
I14
I13
I12
I14
I13
I12
I11
•••
I0
I31
I30
I29
•••
•••
I1
I0
I31
I30
•••
I19
I18
I17
I16
I18
I17
I16
I15
I17
I16
I15
I14
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
11100
11101
11110
11111
I3
I2
I1
I0
I2
I1
I0
I31
I1
I0
I31
I30
•••
I20
I19
I18
I17
I19
I18
I17
I16
•••
I6
I5
I4
I3
I5
I4
I3
I2
I4
I3
I2
I1
TABLE 2.
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
Shift Code
Y 31
Y 30
Y 29
•••
Y 16
Y 15
•••
Y2
Y1
Y0
00000
00001
00010
00011
I31
I30
I29
I28
I30
I29
I28
I27
I29
I28
I27
I26
•••
I15
I14
I13
I12
•••
•••
I16
I15
I14
I13
•••
I2
I1
I0
0
I1
I0
0
0
I0
0
0
0
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•••
•••
•••
•
•
•
•
•••
•
•
•••
•
•
•
01111
10000
10001
10010
I16
I15
I14
I13
I15
I14
I13
I12
I14
I13
I12
I11
•••
I0
0
0
0
•••
•••
I1
I0
0
0
•••
0
0
0
0
0
0
0
0
0
0
0
0
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
11100
11101
11110
11111
I3
I2
I1
I0
I2
I1
I0
0
I1
I0
0
0
•••
0
0
0
0
0
0
0
0
•••
0
0
0
0
0
0
0
0
0
0
0
0
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
The shift array outputs are applied to
a 2:1 multiplexer controlled by the
MS/LS select line. This multiplexer
makes available at the output pins
either the most significant or least
significant 16 outputs of the shift
array.
PRIORITY ENCODER
FILL MODE SHIFT CODE DEFINITIONS — LEFT SHIFT
•••
significant bit of a 6-bit two’s complement shift code, comprised of R/L
concatenated with the SI4–SI0 lines.
Thus a positive shift code (R/L = 0)
results in a left shift of 0–31 positions,
and a negative code (R/L = 1) a right
shift of up to 32 positions. The LSH32
can thus effectively select any contiguous 32-bit field out of a (sign extended
and zero filled) 96-bit "input."
The 32-bit input bus drives a priority
encoder which is used to determine
the first significant position for
purposes of normalization. The
priority encoder produces a five-bit
code representing the location of the
first non-zero bit in the input word.
Code assignment is such that the
priority encoder output represents the
number of shift positions required to
left align the first non-zero bit of the
input word. Prior to the priority
encoder, the input bits are individually exclusive OR’ed with the SIGN
input. This allows normalization in
floating point systems using two’s
complement mantissa representation.
A negative value in two’s complement
representation will cause the exclusive
OR gates to invert the input data to
the encoder. As a result the leading
significant digit will always be "1."
This affects only the encoder inputs;
the shift array always operates on the
raw input data. The priority encoder
function table is shown in Table 4.
Special Arithmetic Functions
ffs2
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
TABLE 3.
32-bit Cascadable Barrel Shifter
NORMALIZE MULTIPLXER
FILL MODE SHIFT CODE DEFINITIONS — RIGHT SHIFT
Shift Code
Y 31
Y 30
Y 29
•••
Y 16
Y 15
•••
Y2
Y1
Y0
00000
00001
00010
00011
S
S
S
S
S
S
S
S
S
S
S
S
•••
S
S
S
S
•••
•••
S
S
S
S
•••
S
S
S
I31
S
S
I31
I30
S
I31
I30
I29
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•••
•••
•••
•••
•
•
•
•
•••
•
•
•••
•
•
•
01111
10000
10001
10010
S
S
S
S
S
S
S
S
S
S
S
S
•••
S
I31
I30
I29
•••
•••
S
S
I31
I30
•••
I19
I18
I17
I16
I18
I17
I16
I15
I17
I16
I15
I14
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
11100
11101
11110
11111
S
S
S
S
S
S
S
I31
S
S
I31
I30
•••
I20
I19
I18
I17
I19
I18
I17
I16
•••
I6
I5
I4
I3
I5
I4
I3
I2
I4
I3
I2
I1
TABLE 4.
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
PRIORITY ENCODER FUNCTION TABLE
I31
I30
I29
•••
I16
I15
•••
I2
I1
I0
Shift Code
1
0
0
X
1
0
X
X
1
•••
X
X
X
•••
•••
X
X
X
•••
X
X
X
X
X
X
X
X
X
00000
00001
00010
•
•
•
•••
•
•
•••
•
•
•
•
•••
•••
•
•
•
•••
•
•
•••
•
•
•
•
0
0
0
0
0
0
0
0
0
•••
X
1
0
•••
•••
1
0
0
•••
X
X
X
X
X
X
X
X
X
01111
10000
10001
•
•
•
•••
•
•
•••
•
•
•
•
•
•
•
•••
•
•
•••
•
•
•
•
0
0
0
0
0
0
0
0
0
•••
0
0
0
0
0
0
•••
0
0
0
1
0
0
X
1
0
11110
11111
11111
•••
•••
•••
•••
•••
•••
The NORM input, when asserted
results in the priority encoder output
driving the internal shift code inputs
directly. It is exactly equivalent to
routing the SO4 –SO 0 outputs back to
the SI4 –SI0 inputs. The NORM input
provides faster normalization of 32-bit
data by avoiding the delay associated
with routing the shift code off chip.
When using the NORM function, the
LSH32 should be placed in fill mode,
with the R/L input low.
APPLICATIONS EXAMPLES
Normalization of mantissas up to 32
bits can be accomplished directly by a
single LSH32. The NORM input is
asserted, and fill mode and left shift
are selected. The normalized mantissa
is then available at the device output
in two 16-bit segments, under the
control of the output data multiplexer
select, the MS/LS.
If it is desirable to avoid the necessity
of multiplexing output data in 16-bit
segments, two LSH32 devices can be
used in parallel. Both devices receive
the same input word, with the MS/LS
select line of one wired high, and the
other low. Each device will then
independently determine the shift
distance required for normalization,
and the full 32 bits of output data will
be available simultaneously.
Special Arithmetic Functions
3
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
LONG-WORD NORMALIZATION
(MULTIPLE CYCLES)
Normalization of floating point
mantissas longer than 32 bits can be
accomplished by cascading LSH32
units. When cascading for normalization, the device inputs are overlapped
such that each device lower in priority
than the first shares 16 inputs with its
more significant neighbor. Fill mode
and left shift are selected, however,
internal normalization (NORM) is not
used. The most significant result half
of each device is enabled to the
output. The shift out (SO 4 –SO 0) lines
of the most significant slice are
connected to the shift in lines of all
slices, including the first. The exception is that all SI4 lines are grounded,
limiting the shift distance to 16
positions. The shift distance required
for normalization is produced by the
priority encoder in the most significant slice. The priority encoder will
produce the shift code necessary to
normalize the input word if the
leading non-zero digit is found in the
upper 16 bits. If this is the case, the
number of shift positions necessary to
accomplish normalization is placed on
the SO 4 –SO 0 outputs for use by all
slices, and the appropriate 0–15 bit
shift is accomplished. If the upper 16
bits are all zero, then the maximum
shift of 15 places is executed. Single
clock normalization requiring shifts
longer than 16 bits can be accomplished by a bank-select technique
described below.
SINGLE CYCLE LONG-WORD
NORMALIZATION
An extension of the above concept is a
single clock normalization of long
words (potentially requiring shifts of
more than 15 places). The arrangement of LSH32s required is shown in
Figure 1. Cascading of LSH32 units is
accomplished by connecting the SI3 –
SI0 input lines of each unit to the SO 3 –
SO 0 outputs of the most significant
device in the row as before. Essen-
FIGURE 1. SINGLE CYCLE LONG-WORD NORMALIZATION USING LSH32S
I 63 -I 48
I 47 -I 32
I 31 -I 16
I 15 -I 0
0
MSBs
4
PRIORITY
ENCODE
2:4
DECODE
LSH32
SI3-0
SO 4-0
OE
I 47 -I 32
4
4
LSH32
SI3-0
SO 4-0
OE
4
LSH32
SI3-0
OE
OE
I 15 -I 0
5
4
4
LSH32
SI3-0
SI3-0
OE
LSH32
SI3-0
OE
SI4
0
4
LSH32
I 15 -I 0
I 16 -I 0
4
4
I 31 -I 16
LSH32
SI3-0
SO 4-0
OE
I 31 -I 16
5
LSH32
SI3-0
OE
SI4
0
5
4
LSH32
SI3-0
OE
SI4
0
LSH32
SO 4-0
SI3-0
OE
SI4
5
Y 63 -Y 48
Y 47 -Y 32
Y 31 -Y 16
Y 15 -Y 0
Special Arithmetic Functions
ffs4
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
tially the LSH32s are arranged in
multiple rows or banks such that the
inputs to successive rows are leftshifted by 16 positions. The outputs
of each row are multiplexed onto a
three-state bus. The normalization
problem then reduces to selecting
from among the several banks that
one which has the first non-zero bit
of the input value among its 16 most
significant positions. If the most
significant one in the input file was
within the upper 16 locations of a
given bank, the SO 4 output of the
most significant slice in that bank will
be low. Single clock normalization
can thus be accomplished simply by
enabling onto the three-state output
bus the highest priority bank in which
this condition is met. In this way the
input word will be normalized
regardless of the number of shift
positions required to accomplish this.
32-bit Cascadable Barrel Shifter
The number of shift positions can be
determined simply by concatenation
of the SO 3 –SO 0 outputs of the most
significant slice in the selected row
with the encoded Output Enable-bits
determining the row number. Note
that lower rows need not be fully
populated. This is because they
represent left shifts in multiples of 16
positions, and the lower bits of the
output word will be zero filled. In
order to accomplish this zero fill, the
least significant device in each row is
always enabled, and the row select is
instead connected to the SI4 input.
This will force the shift length of the
least significant device to a value
greater than 15 whenever the row
containing that device is not selected.
This results in zero fill being accomplished by the equivalently positioned
slice in a higher bank, as shown in the
diagram.
BLOCK FLOATING POINT
With a small amount of external logic,
block floating point operations are
easily accomplished by the LSH32.
Data resulting from a vector operation
are applied to the LSH32 with the
NORM-input deasserted. The SO 4 –
SO 0 outputs fill then represent the
normalization shift distance for each
vector element in turn. By use of an
external latch and comparator, the
maximum shift distance encountered
across all elements in the vector is
saved for use in the next block operation (or block normalization). During
this subsequent pass through the data,
the shift code saved from the previous
pass is applied uniformly across all
elements of the vector. Since the
LSH32 is not used in the internal
normalize mode, this operation can be
pipelined, thereby obtaining the
desired shift distance for the next pass
while simultaneously applying the
normalization required from the
previous pass.
Special Arithmetic Functions
5
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
MAXIMUM RATINGS Above which useful life may be impaired (Notes 1, 2, 3, 8)
Storage temperature ........................................................................................................... –65°C to +150°C
Operating ambient temperature ........................................................................................... –55°C to +125°C
VCC supply voltage with respect to ground ............................................................................ –0.5 V to +7.0 V
Input signal with respect to ground ........................................................................................ –3.0 V to +7.0 V
Signal applied to high impedance output ............................................................................... –3.0 V to +7.0 V
Output current into low outputs ............................................................................................................. 25 mA
Latchup current ............................................................................................................................... > 400 mA
OPERATING CONDITIONS To meet specified electrical and switching characteristics
Mode
Temperature Range (Ambient)
Active Operation, Commercial
Active Operation, Military
Supply Voltage
0°C to +70°C
4.75 V ≤ VCC ≤ 5.25 V
–55°C to +125°C
4.50 V ≤ VCC ≤ 5.50 V
ELECTRICAL CHARACTERISTICS Over Operating Conditions (Note 4)
Symbol
Parameter
Test Condition
Min
VOH
Output High Voltage
VCC = Min., IOH = –2.0 mA
VOL
Output Low Voltage
VCC = Min., IOL = 8.0 mA
VIH
Input High Voltage
VIL
Input Low Voltage
(Note 3)
IIX
Input Current
IOZ
Typ
Max
2.4
Unit
V
0.4
V
2.0
VCC
V
0.0
0.8
V
Ground ≤ VIN ≤ VCC (Note 12)
±20
µA
Output Leakage Current
Ground ≤ VOUT ≤ VCC (Note 12)
±20
µA
ICC1
VCC Current, Dynamic
(Notes 5, 6)
30
mA
ICC2
VCC Current, Quiescent
(Note 7)
1.5
mA
10
Special Arithmetic Functions
ffs6
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
SWITCHING CHARACTERISTICS
COMMERCIAL OPERATING RANGE (0°C to +70°C) Notes 9, 10 (ns)
Symbol
LSH32–
1234567890123456
1234567890123456
1234567890123456
*
42
32
1234567890123456
1234567890123456
1234567890123456
Min
Max
Min
Max
1234567890123456
1234567890123456
42
32
1234567890123456
1234567890123456
1234567890123456
1234567890123456
75
60
1234567890123456
1234567890123456
1234567890123456
55
42
1234567890123456
1234567890123456
1234567890123456
52
40
1234567890123456
1234567890123456
1234567890123456
28
24
1234567890123456
1234567890123456
1234567890123456
20
20
1234567890123456
1234567890123456
1234567890123456
1234567890123456
20
20
1234567890123456
Parameter
tIY
I, SIGN Inputs to Y Outputs
tIYN
I, SIGN Inputs to Y Outputs, Normalize Mode
tISO
I, SIGN Inputs to SO Outputs
tSIY
SI, RIGHT/LEFT to Y Outputs
tMSY
MS/LS Select to Y Outputs
tDIS
Three-State Output Disable Delay (Note 11)
tENA
Three-State Output Enable Delay (Note 11)
20
Min
Max
20
20
20
20
15
15
15
MILITARY OPERATING RANGE (–55°C to +125°C) Notes 9, 10 (ns)
Symbol
1234567890123456789012345678901212345678901234
LSH32–
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
*
50
40*
30*
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
Min
Max
Min
Max
Min
Max
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
50
40
30
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
85
75
58
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
65
52
42
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
62
52
40
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
32
26
24
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
22
20
17
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
1234567890123456789012345678901212345678901234
22
20
17
1234567890123456789012345678901212345678901234
Parameter
tIY
I, SIGN Inputs to Y Outputs
tIYN
I, SIGN Inputs to Y Outputs, Normalize Mode
tISO
I, SIGN Inputs to SO Outputs
tSIY
SI, RIGHT/LEFT to Y Outputs
tMSY
MS/LS Select to Y Outputs
tDIS
Three-State Output Disable Delay (Note 11)
tENA
Three-State Output Enable Delay (Note 11)
SWITCHING WAVEFORMS
I31-I0
SIGN
SI4-SI0
RIGHT/LEFT
MS/LS
tIY, tIYN
SO4-SO0
tMSY
tISO
Y31-Y0
tSIY
OE
tDIS
Y31-Y0
HIGH IMPEDANCE
tENA
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*DISCONTINUED SPEED GRADE
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Special Arithmetic Functions
7
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
NOTES
1. Maximum Ratings indicate stress
specifications only. Functional operation of these products at values beyond
those indicated in the Operating Conditions table is not implied. Exposure to
maximum rating conditions for extended periods may affect reliability.
9. AC specifications are tested with
input transition times less than 3 ns,
output reference levels of 1.5 V (except
tDIS test), and input levels of nominally
0 to 3.0 V. Output loading may be a
resistive divider which provides for
specified IOH and IOL at an output
voltage of VOH min and VOL max
2. The products described by this spec- respectively. Alternatively, a diode
ification include internal circuitry de- bridge with upper and lower current
signed to protect the chip from damagsources of IOH and I OL respectively,
ing substrate injection currents and ac- and a balancing voltage of 1.5 V may be
cumulations of static charge. Neverthe- used. Parasitic capacitance is 30 pF
less, conventional precautions should minimum, and may be distributed.
be observed during storage, handling,
and use of these circuits in order to This device has high-speed outputs caavoid exposure to excessive electrical pable of large instantaneous current
stress values.
pulses and fast turn-on/turn-off times.
As a result, care must be exercised in the
3. This device provides hard clamping of testing of this device. The following
transient undershoot and overshoot. In- measures are recommended:
put levels below ground or above VCC
will be clamped beginning at –0.6 V and a. A 0.1 µF ceramic capacitor should be
VCC + 0.6 V. The device can withstand installed between VCC and Ground
indefinite operation with inputs in the leads as close to the Device Under Test
range of –0.5 V to +7.0 V. Device opera- (DUT) as possible. Similar capacitors
tion will not be adversely affected, how- should be installed between device VCC
ever, input current levels will be well in and the tester common, and device
ground and tester common.
excess of 100 mA.
4. Actual test conditions may vary from b. Ground and VCC supply planes
those designated but operation is guar- must be brought directly to the DUT
anteed as specified.
socket or contactor fingers.
5. Supply current for a given applica- c. Input voltages should be adjusted to
tion can be accurately approximated by: compensate for inductive ground and VCC
noise to maintain required DUT input
NCV2 F
levels relative to the DUT ground pin.
4
where
10. Each parameter is shown as a minN = total number of device outputs
C = capacitive load per output
V = supply voltage
F = clock frequency
6. Tested with all outputs changing every cycle and no load, at a 5 MHz clock
rate.
7. Tested with all inputs within 0.1 V of
VCC or Ground, no load.
8. These parameters are guaranteed
but not 100% tested.
11. For the tENA test, the transition is
measured to the 1.5 V crossing point
with datasheet loads. For the tDIS test,
the transition is measured to the
±200mV level from the measured
steady-state output voltage with
±10mA loads. The balancing voltage, V TH , is set at 3.5 V for Z-to-0
and 0-to-Z tests, and set at 0 V for Zto-1 and 1-to-Z tests.
12. These parameters are only tested at
the high temperature extreme, which is
the worst case for leakage current.
FIGURE A. OUTPUT LOADING CIRCUIT
S1
DUT
IOL
VTH
CL
IOH
FIGURE B. THRESHOLD LEVELS
tENA
OE
Z
tDIS
1.5 V
1.5 V
3.5V Vth
0
1.5 V
1.5 V
Z
1
VOL*
0.2 V
VOH*
0.2 V
0
Z
1
Z
0V Vth
VOL* Measured VOL with IOH = –10mA and IOL = 10mA
VOH* Measured VOH with IOH = –10mA and IOL = 10mA
imum or maximum value. Input requirements are specified from the point
of view of the external system driving
the chip. Setup time, for example, is
specified as a minimum since the external system must supply at least that
much time to meet the worst-case requirements of all parts. Responses from
the internal circuitry are specified from
the point of view of the device. Output
delay, for example, is specified as a
maximum since worst-case operation of
any device always provides data within
that time.
Special Arithmetic Functions
ffs8
08/16/2000–LDS.32-Q
LSH32
DEVICES INCORPORATED
32-bit Cascadable Barrel Shifter
ORDERING INFORMATION
I29
I28
I27
I26
I25
I24
I23
I22
I21
I20
I19
I18
I17
I16
I15
I14
GND
68-pin
10
9
8
7
6
5
4
3
2
1 68 67 66 65 64 63 62 61
60
11
59
12
58
13
57
14
56
15
55
16
54
17
18
19
Top
View
53
52
51
20
50
21
49
22
48
23
47
24
46
25
45
26
44
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
GND
I13
I12
I11
I10
I9
I8
I7
I6
I5
I4
I3
I2
I1
I0
VCC
VCC
Y30/14
Y29/13
Y28/12
Y27/11
Y26/10
Y25/9
Y24/8
Y23/7
Y22/6
Y21/5
Y20/4
Y19/3
Y18/2
Y17/1
Y16/0
OE
MS/LS
I30
I31
SIGN
SO4
SO3
SO2
SO1
SO0
NORM
SI4
SI3
SI2
SI1
SI0
R/L
F/W
Y31/15
Speed
Plastic J-Lead Chip Carrier
(J2)
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68-pin
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1
2
3
4
5
6
7
8
9
10
11
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A
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I29
I28
I14
I26
I24
I22
I20
I18
I16
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B
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I31
I30
I27
I25
I23
I21
I19
I17
I15 GND GND
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C
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SO4 SIGN
I12
I13
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D
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SO2 SO3
I10
I11
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E
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Top View
SO0 SO1
I8
I9
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Through Package
F
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SI4 NORM
I6
I7
(i.e., Component Side Pinout)
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G
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SI2
SI3
I4
I5
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H
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SI0
SI1
I2
I3
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J
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F/W R/L
I0
I1
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K
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Y31/15 Y30/14 Y28/12 Y26/10 Y24/8 Y22/6 Y20/4 Y18/2 Y16/0 VCC VCC
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L
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Y29/13 Y27/11 Y25/9 Y23/7 Y21/5 Y19/3 Y17/1 OE MS/LS
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Discontinued Package
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Ceramic Pin Grid Array
(G1)
0°C to +70°C — COMMERCIAL SCREENING
32 ns
20 ns
LSH32JC32
LSH32JC20
–55°C to +125°C — COMMERCIAL SCREENING
–55°C to +125°C — MIL-STD-883 COMPLIANT
Special Arithmetic Functions
9
08/16/2000–LDS.32-Q