87C51 Intel Corporation, 87C51 Datasheet - Page 14

• Manufacturer Part Number: 87C51
• Description: CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER
• Manufacturer: Intel Corporation

87C51 80C51BH 80C31BH
EXTERNAL MEMORY CHARACTERISTICS
All parameter values apply to all devices unless otherwise indicated In this table 87C51 BH refers to
87C51 BH 87C51-1 BH-1 and 87C51-2 BH-2 (Continued)
EXTERNAL PROGRAM MEMORY READ CYCLE
EXTERNAL DATA MEMORY READ CYCLE
14
TWHQX
TQVWH
TRLAZ
TWHLH
Symbol
Data Hold After WR
Data Valid to WR High
RD Low to Address Float
RD or WR High to ALE High
87C51 BH
87C51-24 BH-24
87C51 BH
87C51-24 BH-24
87C51 BH
87C51-24 BH-24
Parameter
Min
433
33
43
12 MHz
Max
123
0
Min
222
12
7
24 MHz
Max
71
0
Oscillator
7TCLCL
7TCLCL
TCLCL
TCLCL
TCLCL
TCLCL
Min
b
b
b
b
b
b
Variable
50
35
150
40
30
70
TCLCL
TCLCL
Max
0
a
a
40
30
272335 –12
272335 –13
Units
ns
ns
ns
ns
ns
ns
ns