Intel MCS48 User Manual page 308

8253/8253-5
A.C.
CHARACTERISTICS
t a
= o°c
to
70°c
;
v
cc
=
5.ov ±5%;
gnd
= ov
Bus
Parameters (Note
1)
Read
Cycle:
SYMBOL
PARAMETER
8253
MIN.
MAX.
8253-5
MIN.
MAX.
UNIT
*AR
Address
Stable
Before R
EAD
50
30
ns
*RA
Address Hold Time
for
READ
5 5
ns
tRR
READ
Pulse
Width 400
300
ns
tRD
Data Delay
From
R
EAD^I
300 200
ns
tDF
READ
to Data
Floating
25 125
25 100
ns
l RV
Recovery
Time Between
READ
and
Any
Other Control Signal
1
1
AS
Write Cycle:
SYMBOL PARAMETER
82
MIN.
53
MAX.
8253-5
MIN.
MAX. UNIT
50 30
*AW
Address
Stable
Before
WRITE
ns
*WA
Address Hold Time
for
WR
ITE 30 30 ns
*WW
WRITE
Pulse
Width
400
300
ns
tDW Data Set
Up Time
for
WR
ITE
300 250
ns
twD Data
Hold Time
for
WRITE
40
30 ns
1 1
tRV
Recovery Time Between
WRITE
and
Any
Other Control Signal
MS
Notes:
1.
AC
timings
measuredat
Vqh
=
2.2,
Vol
=
0-8
2.
Test Conditions:
8253, C[_
=
100pF; 8253-5:
C[_- 150pF.
Write Timing:
X
%J
X
X
Read
Timing:
X
P
^y/////////////////
X
7777777777777777777;
HIGH IMPEDANCE
Input
Waveforms
for
A.C.
Tests
2.4
0.45
8-18
00745A