87C54-20 Intel Corporation, 87C54-20 Datasheet - Page 10

• Manufacturer Part Number: 87C54-20
• Description: CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER WITH 16 KBYTES USER PROGRAMMABLE EPROM
• Manufacturer: Intel Corporation

AUTOMOTIVE 87C54 87C54-20
EXPLANATION OF THE AC SYMBOLS
Each timing symbol has 5 characters The first char-
acter is always a ‘T’ (stands for time) The other
characters depending on their positions stand for
the name of a signal or the logical status of that
signal The following is a list of all the characters and
what they stand for
AC CHARACTERISTICS
for Port 0 ALE PROG and PSEN
ADVANCED INFORMATION CONTACT INTEL FOR DESIGN-IN INFORMATION
EXTERNAL MEMORY CHARACTERISTICS
10
1 T
T
T
T
T
T
T
T
T
T
T
T
Symbol
LHLL
AVLL
LLAX
LLIV
LLPL
PLPH
PLIV
PXIX
PXIZ
AVIV
PLAZ
A Address
C Clock
D Input Data
H Logic level HIGH
I Instruction (program memory contents)
L Logic level LOW or ALE
CLCL
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
Address Valid to
Valid Instruction In
PSEN Low to
Address Float
Parameter
(T
e
A
e b
100 pF Load Capacitance for All Other Outputs
Min
127
205
43
53
53
0
12 MHz Oscillator
40 C to
a
125 C V
Max
234
145
312
59
10
For example
P PSEN
Q Output Data
R RD signal
T
T Time
V Valid
W WR signal
X No longer a valid logic level
Z Float
T
AVLL
LLPL
CC
e
e
e
5V
2 T
3 T
Time from ALE Low to PSEN Low
Time from Address Valid to ALE Low
T
T
T
CLCL
CLCL
CLCL
g
CLCL
CLCL
Min
20% V
3 5
0
Variable Oscillator
87C54 87C54-20
b
b
b
b
b
40
30
30
40
45
SS
e
4 T
3 T
4 T
3 T
5 T
T
T
e
0V Load Capacitance
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
CLCL
80 pF)
16 20
Max
10
b
b
b
b
b
b
b
25
20
100
105
75
90
105
Units
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns