w78e516b Winbond Electronics Corp America, w78e516b Datasheet - Page 24

• Manufacturer Part Number: w78e516b
• Description: 8-bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

7.3 A.C. 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 (T
usually experience less than a ±20 nS variation. The numbers below represent the performance
expected from a 0.6 micron CMOS process when using 2 and 4 mA output buffers.
7.3.1 Clock Input Waveform
Notes:
7.3.2 Program Fetch Cycle
Notes:
Address Valid to ALE Low
Address Hold from ALE Low
ALE Low to
PSEN
Data Hold after PSEN High
Data Float after PSEN High
ALE Pulse Width
PSEN Pulse Width
Operating Speed
Clock Period
Clock High
Clock Low
1. The clock may be stopped indefinitely in either state.
2. The T
3. There are no duty cycle requirements on the XTAL1 input.
1. P0.0 − P0.7, P2.0 − P2.7 remain stable throughout entire memory cycle.
2. Memory access time is 3 T
3. Data have been latched internally prior to PSEN going high.
4. "Δ " (due to buffer driving delay and wire loading) is 20 nS.
Low to Data Valid
PARAMETER
PARAMETER
CP
PSEN
specification is used as a reference in other specifications.
Low
XTAL1
CP
.
SYMBOL
SYMBOL
T
T
T
T
T
T
T
T
Fop
T
Tch
Tcl
PSW
AAH
PDA
PDH
ALW
AAS
PDZ
APL
CP
T
CH
- 24 -
1 T
1 T
1 T
2 T
3 T
F
MIN.
MIN.
OP,
25
10
10
0
CP
CP
CP
0
0
CP
CP
-
-Δ
-Δ
-Δ
-Δ
-Δ
T
CP
T
2 T
3 T
CL
TYP.
TYP.
Publication Release Date: April 22, 2008
-
-
-
-
-
-
-
-
-
-
CP
CP
MAX.
2 T
1 T
1 T
MAX.
40
-
-
-
-
-
-
-
-
CP
CP
CP
CP
), and actual parts will
UNIT
W78E516B
MHz
UNIT
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
Revision A12
NOTES
NOTES
1, 4
1
2
3
3
4
4
2
3
4
4