AT89C51-12 ATMEL [ATMEL Corporation], AT89C51-12 Datasheet - Page 10

• Manufacturer Part Number: AT89C51-12
• Description: 8-Bit Microcontroller with 4K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

AC Characteristics
(Under Operating Conditions; Load Capacitance for Port 0, ALE/PROG, and PSEN = 100 pF; Load Capacitance for all other
outputs = 80 pF)
External Program and Data Memory Characteristics
4-38
Symbol
1/t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
LHLL
AVLL
LLAX
LLIV
LLPL
PLPH
PLIV
PXIX
PXIZ
PXAV
AVIV
PLAZ
RLRH
WLWH
RLDV
RHDX
RHDZ
LLDV
AVDV
LLWL
AVWL
QVWX
QVWH
WHQX
RLAZ
WHLH
CLCL
Parameter
Oscillator Frequency
ALE Pulse Width
Address Valid to ALE Low
Address Hold After ALE Low
ALE Low to Valid Instruction In
ALE Low to PSEN Low
PSEN Pulse Width
PSEN Low to Valid Instruction In
Input Instruction Hold After PSEN
Input Instruction Float After PSEN
PSEN to Address Valid
Address to Valid Instruction In
PSEN Low to Address Float
RD Pulse Width
WR Pulse Width
RD Low to Valid Data In
Data Hold After RD
Data Float After RD
ALE Low to Valid Data In
Address to Valid Data In
ALE Low to RD or WR Low
Address to RD or WR Low
Data Valid to WR Transition
Data Valid to WR High
Data Hold After WR
RD Low to Address Float
RD or WR High to ALE High
AT89C51
Min
127
205
400
400
200
203
433
12 MHz Oscillator
43
48
43
75
23
33
43
0
0
Max
233
145
312
252
517
585
300
123
10
59
97
0
6t
6t
7t
2t
3t
3t
4t
t
t
t
t
t
t
16 to 24 MHz Oscillator
CLCL
CLCL
CLCL
t
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
Min
0
0
0
-13
-20
-13
-100
-100
-20
-120
-20
-20
-40
-20
-8
-50
-75
8t
9t
3t
4t
3t
5t
5t
2t
t
t
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
Max
24
10
0
+25
-10
-150
-165
+50
-65
-45
-55
-90
-28
Units
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns