DS80C320 Datasheet, PDF (29/42 Pages) Dallas Semiconductor – High-Speed/Low-Power Micro

DS80C323 AC ELECTRICAL CHARACTERISTICS
PARAMETER
SYMBOL 18 MHz 18 MHz VARIABLE
MIN
MAX
CLOCK
Oscillator Frequency
(Ext. Osc.)
MIN
1/t_CLCL
0
18
0
(Ext. Crystal)
1
18
1
ALE Pulse Width
Port 0 Address Valid
to ALE Low
t_LHLL
73
t_AVLL
16
1.5t_CLCL -10
0.5t_CLCL -11
Address Hold After
ALE Low
t_LLAX1
8
note 5
0.25t_CLCL -5
Address Hold After
t_LLAX2
20
0.5t_CLCL -7
ALE Low for MOVX WR
ALE Low to Valid
t_LLIV
112
Instruction In
ALE Low to PSEN Low
t_LLPL
6
0.25t_CLCL -7
PSEN Pulse Width
t_PLPH
118
2.25t_CLCL -7
PSEN Low to Valid
t_PLIV
104
Instruction In
Input Instruction Hold
t_PXIX
0
0
After PSEN
Input Instruction Float
t_PXIZ
51
After PSEN
Port 0 Address to Valid
t_AVIV1
140
Instruction In
Port 2 Address to Valid
t_AVIV2
162
Instruction In
PSEN Low to
t_PLAZ
note 5
Address Float
DS80C320/DS80C323
VARIABLE
CLOCK
MAX
18
18
UNITS
MHz
ns
ns
note 5
ns
ns
2.5t_CLCL -27
ns
ns
ns
2.25t_CLCL -21
ns
ns
t_CLCL -5
ns
3t_CLCL -27
ns
3.5t_CLCL -33
ns
note 5
ns
NOTES FOR DS80C323 AC ELECTRICAL CHARACTERISTICS:
All parameters apply to both commercial and industrial temperature range operation unless otherwise
noted. AC timing characteristics valid for oscillator frequency > 16 MHz.
1. All signals rated over operating temperature at 18 MHz.
2. All signals characterized with load capacitance of 80 pF except Port 0, ALE, PSEN , RD and WR at
100 pF. Note that loading should be approximately equal for valid timing.
3. Interfacing to memory devices with float times (turn off times) over 35 ns 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.
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