Datasheet

DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
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AC CHARACTERISTICS—DS80C320
33MHz VARIABLE CLOCK
PARAMETER SYMBOL
MIN MAX MIN MAX
UNITS
External
Oscillator
0 33 0 33
Oscillator
Frequency
External
Crystal
1/t
CLCL
1 33 1 33
MHz
ALE Pulse Width t
LHLL
34 1.5t
CLCL
-11 ns
Port 0 Address Valid to
ALE Low
t
AVLL
4 0.5t
CLCL
-11 ns
Address Hold After
ALE Low
t
LLAX1
2 (Note 5) 0.25t
CLCL
-5 (Note 5) ns
Address Hold After
ALE Low for MOVX
WR
t
LLAX2
6 0.5t
CLCL
-9 ns
ALE Low to Valid
Instruction In
t
LLIV
49 2.5t
CLCL
-27 ns
ALE Low to PSEN Low
t
LLPL
0.5 0.25t
CLCL
-7 ns
PSEN Pulse Width
t
PLPH
61 2.25t
CLCL
-7 ns
PSEN Low to Valid
Instruction In
t
PLIV
48 2.25t
CLCL
-21 ns
Input Instruction Hold
After
PSEN
t
PXIX
0 0 ns
Input Instruction Float
After
PSEN
t
PXIZ
25 t
CLCL
-5 ns
Port 0 Address to Valid
Instruction In
t
AVIV1
64 3t
CLCL
-27 ns
Port 2 Address to Valid
Instruction In
t
AVIV2
73 3.5t
CLCL
-33 ns
PSEN
Low to Address Float
t
PLAZ
(Note 5) (Note 5) ns
NOTES FOR DS80C320 AC ELECTRICAL CHARACTERISTICS
All parameters apply to both commercial and industrial temperature operation unless otherwise noted. Specifications to -40°C
are guaranteed by design and are not production tested. AC electrical characteristics assume 50% duty cycle for the oscillator,
oscillator frequency > 16MHz, and are not 100% tested, but are guaranteed by design.
1. All signals rated over operating temperature at 33MHz.
2. All signals characterized with load capacitance of 80pF except Port 0, ALE,
PSEN , RD and WR at 100pF.
Note that loading should be approximately equal for valid timing.
3. Interfacing to memory devices with float times (turn off times) over 30ns may cause contention. This will not
damage the parts but will cause an increase in operating current.
4. Specifications assume a 50% duty cycle for the oscillator. Port 2 timing will change with the duty cycle
variations.
5. Address is held in a weak latch until over driven by external memory.