W78LE54 Datasheet, PDF (14/22 Pages) Winbond – 8-BIT MTP MICROCONTROLLER

Preliminary W78LE54
AC CHARACTERISTICS
The AC specifications are a function of the particular process used to manufacture the part, the
ratings of the I/O buffers, the capacitive load, and the internal routing capacitance. Most of the
specifications can be expressed in terms of multiple input clock periods (TCP), and actual parts will
usually experience less than a ±20 nS variation. The numbers below represent the performance
expected from a 0.6micron CMOS process when using 2 and 4 mA output buffers.
Clock Input Waveform
XTAL1
T_CH
TCL
F OP, TCP
PARAMETER
Operating Speed
Clock Period
Clock High
Clock Low
SYMBOL
FOP
TCP
TCH
TCL
MIN.
0
25
10
10
Notes:
1. The clock may be stopped indefinitely in either state.
2. The TCP specification is used as a reference in other specifications.
3. There are no duty cycle requirements on the XTAL1 input.
TYP.
-
-
-
-
MAX.
24
-
-
-
UNIT
MHz
nS
nS
nS
NOTES
1
2
3
3
Program Fetch Cycle
PARAMETER
SYMBOL MIN.
Address Valid to ALE Low
Address Hold from ALE Low
ALE Low to PSEN Low
PSEN Low to Data Valid
Data Hold after PSEN High
Data Float after PSEN High
ALE Pulse Width
PSEN Pulse Width
TAAS
TAAH
TAPL
TPDA
TPDH
TPDZ
TALW
TPSW
1 TCP -∆
1 TCP -∆
1 TCP -∆
-
0
0
2 TCP -∆
3 TCP -∆
Notes:
1. P0.0−P0.7, P2.0−P2.7 remain stable throughout entire memory cycle.
2. Memory access time is 3 TCP.
3. Data have been latched internally prior to PSEN going high.
4. "∆" (due to buffer driving delay and wire loading) is 20 nS.
TYP.
-
-
-
-
-
-
2 TCP
3 TCP
MAX.
-
-
-
2 TCP
1 TCP
1 TCP
-
-
UNIT
nS
nS
nS
nS
nS
nS
nS
nS
NOTES
4
1, 4
4
2
3
4
4
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