w78l812a Winbond Electronics Corp America, w78l812a Datasheet - Page 22

• Manufacturer Part Number: w78l812a
• Description: 8-bit Mcu Series 80c51-based
• Manufacturer: Winbond Electronics Corp America

9.2
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
4. " Δ " (due to buffer driving delay and wire loading) is 20 nS.
9.3
Notes:
1. Data memory access time is 8 T
2. " Δ " (due to buffer driving delay and wire loading) is 20 nS.
9.4
Note: " Δ " (due to buffer driving delay and wire loading) is 20 nS.
Address Valid to ALE Low
Address Hold from ALE Low
ALE Low to
Data Hold after PSEN High
Data Float after PSEN High
ALE Pulse Width
ALE Low to RD Low
Data Hold from RD High
Data Float from RD High
ALE Low to WR Low
Data Valid to WR Low
Data Hold from WR High
PSEN
PSEN Pulse Width
RD Low to Data Valid
RD Pulse Width
WR Pulse Width
Program Fetch Cycle
Data Read Cycle
Data Write Cycle
Low to Data Valid
PARAMETER
PARAMETER
PARAMETER
PSEN
Low
CP
.
CP
.
SYMBOL
T
T
PSEN
T
T
T
DAR
DDA
DDH
DRD
SYMBOL
DDZ
SYMBOL
T
T
T
T
T
T
T
T
PSW
ALW
T
T
AAS
AAH
PDA
PDH
PDZ
T
APL
T
going high.
DAW
DWD
DWR
DAD
3 T
6 T
MIN.
- 22 -
CP
CP
0
0
1 T
1 T
1 T
2 T
3 T
-
MIN.
-Δ
-Δ
3 T
1 T
1 T
6 T
CP
CP
CP
CP
CP
0
0
-
MIN.
-Δ
-Δ
-Δ
-Δ
-Δ
CP
CP
CP
CP
6 T
TYP.
-Δ
-Δ
-Δ
-Δ
-
-
-
-
W78LE812/W78L812A
CP
2 T
3 T
TYP.
-
-
-
-
-
-
CP
CP
6 T
3 T
TYP.
4 T
2 T
2 T
MAX.
-
-
-
CP
CP
-
2 T
1 T
1 T
MAX.
CP
CP
CP
+Δ
-
-
-
-
-
CP
CP
CP
3 T
MAX.
CP
UNIT
-
-
-
UNIT
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
+Δ
NOTES
NOTES
UNIT
1, 4
1, 2
nS
nS
nS
nS
4
4
2
3
4
4
1
2