MC68882EI25A Datasheet, PDF (18/26 Pages) Freescale Semiconductor, Inc – HCMOS Enhanced Floating-Point Coprocessor

Freescale Semiconductor, Inc.
AC ELECTRICAL SPECIFICATIONS — READ AND WRITE CYCLES (Continued)
Num
Characteristic
16.67 MHz
20 MHz
25 MHz
33.33 MHz
Min Max Min Max Min Max Min Max
Unit
12 ~ Width Asserted {Write)
40
—
38
—
30
—
23
—
ns
13 ~ Width Negated
40
—
38
—
30
—
23
—
ns
13A4
142
15
= Negated to ~ Asserted
~, ~ Asserted to Data-Out Valid) (Read)
~ Negated to Data-Out Invalid (Read)
30
—
30
—
25
—
18
—
ns
—
80
—
60
—
45
—
o—o—o—o
16 ~ Negated to Data-Out High Impedance (Read)
—
50
—
30
—
30
17 Data-In Valid to ~ Asserted (Write)
15
—
10 —
5
— :$ &~~:~ -
ns
18 ~ Negated to Data-In Invalid (Write)
—
—
192 START True to DSACKO and DSACK1 Asserted
15
—
10
—
5
~<:~ ‘(~’
–
n5
7
—
50
—
35
— ,$ ^{‘$~b,. i–}
20
ns
19A7
20
DSACKO Asserted to DSACKI Asserted (Skew)
—
—
DSACKO or DSACKI Asserted to Data-Out Valid
–15
15 –lo
10 - $*., $:.10 ‘ –
5
n5
—
50
—
43 ,j;~:,<p~s 32
—
17
ns
218
START False to DSACKO and DSACK1 Negated
—
50
—
—
_
228
START False to DSACKO and DSACKI High Impedance
—
70
30
—
20
ns
“–
40
–
30
ns
233,8
243
START True to Clock High (Synchronous Read)
Clock Low to Data-Out Valid (Synchronous Read)
.
-
o—o—
ns
—
l,g ! ;,, ,$
80
—
60 .—
45
ns
253S8 START True to Data-Out Valid (Synchronous Read)
— ^{, ~,g *“_}
80+
— 60+
— 45+
1.p:(, 2.5 ‘ 1.5 2.5 1.5 2.5 1.5 2.5
C;:s
263 Clock Low to DSACKO and DSACKI Asserted
(Synchronous Read)
‘+$\..J>,..,.li~~)~.i,i.~i>*,><.$,\$i~i:, ^?’;~75
—
55
—
45
—
30
ns
2j3,8
—
—
START True to DSACKO and DSACK1 As5~~ted
*“,*~7,,\.,!:xJ.:.>.<,,.*,,_ ₇₅₊
— 55+
— 45+
— 30+
(Synchronous Read)
NOTES:
1. Timing measurements are referenced
**>.. : ‘
,+:~~>$,{
t:~~,., ^(~j,
“<$ 1.5
to ~~,.~~m”’a low voltage
2.5 1.5 2.5 1.5 2.5 1.5
of 0.8 volts and a high voltage of 2.0 volts,
2.5
CY:S
unless otherwise
noted, The voltage swing through this&@~~$~$~ould start outside, and pass through, the range such that the rise or fall will be
linear between 0.8 volts and 2.o vol~ “ii~(,:}’
2. These specifications only apply if $&$*~882
bus cycle when ~ was negated~t‘l“, ^{:.;~$:,:.<’~:~~j:.}
has completed all internal operations initiated by the termination of the previous
3. Synchronous read cycles occ~:$o~’when the save or response CIR locations are read.
4. This specification only ap#}?&s~W->ystemsin which back-to-back accesses (read-write or write-write) of the operand CIR can
occur. When the
Immediate.
MC6_.w_~$~&_:~_*,_.$_{:@_&$sed
as a coprocessor to the MC68020/MC68030, this can occur when the addressing mode is
5. If the SIZE pin is g~~~~mped to either VCC or GND, it must have the same setup times as do addresses.
6. If the SIZE pin i/’~t#rapped
to either VCC o—r GND, it mus—t have the same hold times as do addresses.
7. This numbW?~,~edu~ed to 5 nanoseconds if DSACKO and DSACKI have equal loads.
8. START is ti~~iw~xternal signal; rather, it is the logical condition that indicates the start of an access. The logical equation for
this c~,~~~~o ~ m=
~ +~ t R~*~.
9. If a ~’~k~~~$nt access is not a FPCP access, ~ must be negated before the assertion of ~ end/or ~ on the non-FPCP acce~
Tk@#@’~cifications replace the old specifications 8 and 8A (the old specifications implied that in all cases, transitions in CS.
g~u~s~ot
,+,~+<,,..,:,i,‘{:.$,,i>y.$lw.,}.*},
&,:,?:**~:4
<.bk>>lib
occur simultaneously
with transitions of ~ or ~. This is not a.requirement
of the MC68882).
‘$~~~ ELECTRICAL SPECIFICATION DEFINITIONS
The AC specifications presented consist of output de-
lays, input setup and hold times, and signal skew times,
All signals are specified relative to an appropriate edge
ef the clock input and, possibly, relative to one or more
other signals.
The measurement of the AC specifications is defined
by the waveforms shown in Figure 20. In order to test
the parameters guaranteed by Motorola, inputs must be
driven to the voltage levels specified in. Figure 20. Outputs
are specified with minimum and/or maximum limits, as
appropriate, and are measured as shown. Inputs are
specified with minimum and, as appropriate, maximum
setup and hold times, and are measured as shown, Fi-
nally, the measurement for signal-to-signal specifications
are also shown.
Note that the testing levels used to verify conformance
to the AC specifications does not affect the guaranteed
DC operation of the device as specified in the DC electrical
characteristics.
~~. ,
r _{<:, ,}
,~.x,.-..
,*).*/
.:. ‘.
&v‘,,.,,.
MOTOROLA
18
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MC6B682
BR~/Rev.
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3
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