Datasheet

DS80C310
13 of 22
AC ELECTRICAL CHARACTERISTICS (Note 1)
25MHz
VARIABLE
CLOCK
PARAMETER SYMBOL
MIN MAX MIN MAX
UNITS
External Oscillator 0 25 0 25
Oscillator
Frequency
External Crystal
1/t
CLCL
1 25 1 25
MHz
ALE Pulse Width t
LHLL
40
1.5t
CLCL
-
5
ns
Port 0 Address Valid to ALE Low t
AVLL
10
0.5t
CLCL
-
5
ns
Address Hold after ALE Low t
LLAX1
2 (Note 2)
0.5t
CLCL
-
18
(Note 2) ns
ALE Low to Valid Instruction In t
LLIV
56
2.5t
CLCL
-
20
ns
ALE Low to PSEN Low
t
LLPL
7
0.5t
CLCL
-
13
ns
PSEN Pulse Width
t
PLPH
55 2t
CLCL
-5 ns
PSEN Low to Valid Instruction In
t
PLIV
41
2t
CLCL
-
20
ns
Input Instruction Hold after PSEN
t
PXIX
0 0 ns
Input Instruction Float after PSEN
t
PXIZ
26 t
CLCL
-5 ns
Port 0 Address to Valid Instruction In t
AVIV1
71
3t
CLCL
-
20
ns
Port 2 Address to Valid Instruction In t
AVIV2
81
3.5t
CLCL
-
25
ns
PSEN Low to Address Float
t
PLAZ
(Note 2) (Note 2) ns
Note 1:
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40C
are guaranteed by design and not product tested. AC electrical characteristics assume 50% duty cycle for the oscillator, and
are not 100% tested but are guaranteed by design. All signals characterized with load capacitance of 80pF except Port 0, ALE,
PSEN, and WR with 100pF. Interfacing to memory devices with float times (turn-off times) over 25ns can cause contention.
This does not damage the parts, but rather causes an increase in operating current. Port 2 and ALE timing changes in relation
to duty cycle variation.
Note 2:
Address is held in a weak latch until overdriven by external memory.