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W79E217A Datasheet, PDF (193/207 Pages) Winbond – 8-bit Microcontroller
Preliminary W79E217A Data Sheet
25.3 AC Characteristics
Clock
tCHCL
tCLCH
tCLCX
tCLCL
tCHCX
Note: Duty cycle is 50%.
25.3.1 External Clock Characteristics
PARAMETER
Clock High Time
Clock Low Time
Clock Rise Time
Clock Fall Time
SYMBOL
tCHCX
tCLCX
tCLCH
tCHCL
MIN.
12
12
-
-
TYP.
-
-
-
-
MAX.
-
-
10
10
UNITS
nS
nS
nS
nS
NOTES
25.3.2 AC Specification
(VDD − VSS = 5V ±10%, TA = 25°C, Fosc = 20 MHz, unless otherwise specified.)
PARAMETER
Oscillator Frequency
SYMBOL
1/tCLCL
VARIABLE
CLOCK
MIN.
0
0
VARIABLE
CLOCK
MAX.
331
242
ALE Pulse Width
Address Valid to ALE Low
Address Hold After ALE Low
Address Hold After ALE Low for
MOVX Write
tLHLL
tAVLL
tLLAX1
tLLAX2
1.5tCLCL - 5
0.5tCLCL - 5
0.5tCLCL - 5
0.5tCLCL - 5
ALE Low to Valid Instruction In
tLLIV
ALE Low to PSEN Low
tLLPL
0.5tCLCL - 5
2.5tCLCL - 20
PSEN Pulse Width
tPLPH
2.0tCLCL - 5
PSEN Low to Valid Instruction In
tPLIV
2.0tCLCL - 20
Input Instruction Hold After PSEN
tPXIX
0
Input Instruction Float After PSEN
tPXIZ
Port 0 Address to Valid Instr. In
tAVIV1
tCLCL - 5
3.0tCLCL - 20
UNITS
MHz
MHz
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
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Publication Release Date: December 14, 2007
Revision A3.0