W78E51B Winbond, W78E51B Datasheet - Page 14

• Manufacturer Part Number: W78E51B
• Description: 8-BIT MTP MICROCONTROLLER
• Manufacturer: Winbond

Clock Input Waveform
Notes:
1. The clock may be stopped indefinitely in either state.
2. The T
3. There are no duty cycle requirements on the XTAL1 input.
Program Fetch Cycle
Notes:
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. " " (due to buffer driving delay and wire loading) is 20 nS.
Data Read Cycle
Notes:
1. Data memory access time is 8 T
2. " " (due to buffer driving delay and wire loading) is 20 nS.
Operating Speed
Clock Period
Clock High
Clock Low
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
ALE Low to RD Low
RD Low to Data Valid
Data Hold from RD High
Data Float from RD High
RD Pulse Width
CP
PARAMETER
specification is used as a reference in other specifications.
PARAMETER
PARAMETER
CP
XTAL1
.
CP
.
SYMBOL
SYMBOL
T
T
T
T
T
F
T
T
T
SYMBOL
DAR
DDA
DDH
DDZ
DRD
OP
CH
CP
CL
T
T
T
T
T
T
T
T
PSW
ALW
AAH
PDA
PDH
AAS
APL
PDZ
3 T
6 T
T
CH
MIN.
- 14 -
MIN.
CP
CP
0
0
-
25
10
10
1 T
1 T
1 T
2 T
3 T
0
F
MIN.
-
-
OP,
CP
CP
CP
CP
CP
0
0
-
-
-
-
-
-
T
CP
6 T
TYP.
TYP.
T
-
-
-
-
CL
-
-
-
-
CP
2 T
3 T
Preliminary W78E51B
TYP.
-
-
-
-
-
-
CP
CP
3 T
MAX.
MAX.
4 T
2 T
2 T
40
CP
MAX.
2 T
1 T
1 T
-
-
-
-
CP
CP
CP
-
-
-
-
+
-
CP
CP
CP
UNIT
MHz
UNIT
UNIT
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
NOTES
NOTES
NOTES
1, 2
1, 4
1
2
1
2
3
3
4
4
2
3
4
4