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AT89C51RC Datasheet, PDF (29/37 Pages) ATMEL Corporation – 8-bit Microcontroller with 32K Bytes Flash
AT89C51RC
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
Symbol
1/tCLCL
tLHLL
tAVLL
tLLAX
tLLIV
tLLPL
tPLPH
tPLIV
tPXIX
tPXIZ
tPXAV
tAVIV
tPLAZ
tRLRH
tWLWH
tRLDV
tRHDX
tRHDZ
tLLDV
tAVDV
tLLWL
tAVWL
tQVWX
tQVWH
tWHQX
tRLAZ
tWHLH
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
12 MHz Oscillator
Min
Max
127
43
48
233
43
205
145
0
59
75
312
10
400
400
252
0
97
517
585
200
300
203
23
433
33
0
43
123
Variable Oscillator
Min
Max
0
33
2tCLCL-40
tCLCL-25
tCLCL-25
tCLCL-25
3tCLCL-45
0
4tCLCL-65
3tCLCL-60
tCLCL-8
tCLCL-25
5tCLCL-80
10
6tCLCL-100
6tCLCL-100
0
5tCLCL-90
3tCLCL-50
4tCLCL-75
tCLCL-30
7tCLCL-130
tCLCL-25
2tCLCL-28
8tCLCL-150
9tCLCL-165
3tCLCL+50
0
tCLCL-25
tCLCL+25
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
29
1920B–MICRO–11/02