AN87C54 Ver la hoja de datos (PDF) - Intel
Número de pieza
componentes Descripción
Fabricante
AN87C54 Datasheet PDF : 20 Pages
| |||
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
A Address
C Clock
D Input Data
H Logic level HIGH
I Instruction (program memory contents)
L Logic level LOW or ALE
P PSEN
Q Output Data
R RD signal
T Time
V Valid
W WR signal
X No longer a valid logic level
Z Float
For example
TAVLL e Time from Address Valid to ALE Low
TLLPL e Time from ALE Low to PSEN Low
AC CHARACTERISTICS (TA e b40 C to a125 C VCC e 5V g 20% VSS e 0V Load Capacitance
for Port 0 ALE PROG and PSEN e 100 pF Load Capacitance for All Other Outputs e 80 pF)
ADVANCED INFORMATION CONTACT INTEL FOR DESIGN-IN INFORMATION
EXTERNAL MEMORY CHARACTERISTICS
Symbol
Parameter
1 TCLCL Oscillator
Frequency
TLHLL
TAVLL
ALE Pulse Width
Address Valid to
ALE Low
TLLAX
Address Hold After
ALE Low
TLLIV
ALE Low to Valid
Instruction In
TLLPL
ALE Low to PSEN
Low
TPLPH
TPLIV
PSEN Pulse Width
PSEN Low to Valid
Instruction In
TPXIX
Input Instruction
Hold After PSEN
TPXIZ
Input Instruction
Float After PSEN
TAVIV
Address Valid to
Valid Instruction In
TPLAZ
PSEN Low to
Address Float
12 MHz Oscillator
Min
Max
127
43
53
234
53
205
145
0
59
312
10
10
Variable Oscillator
87C54 87C54-20
Min
Max
35
16 20
Units
MHz
2 TCLCL b 40
ns
TCLCL b 40
ns
TCLCL b 30
ns
4 TCLCL b 100
ns
4 TCLCL b 75
TCLCL b 30
ns
3 TCLCL b 45
ns
3 TCLCL b 105
ns
3 TCLCL b 90
0
ns
TCLCL b 25
ns
TCLCL b 20
5 TCLCL b 105 ns
10
ns
Share Link: 