NTE8255 NTE Electronics, Inc., NTE8255 Datasheet - Page 3

• Manufacturer Part Number: NTE8255
• Description: Integrated Circuit Programmable Peripheral Interface
• Manufacturer: NTE Electronics, Inc.

Note 6. Period of Reset pulse must be at least 50μs during or after power on. Subsequent Reset
Note 7.
Note 8. INTR↑ may occur as early as WR↓.
Basic Operation:
Note 9. All conditions not listed are illegal and should be avoided.
Note10. X means “DO NOT CARE”.
OTHER TIMING
WR = 0 to Output
Peripheral Data Before RD
Peripheral Data After RD
ACK Pulse Width
STB Pulse Width
Per. Data Before T.E. of STB
Per. Data After T.E. of STB
ACK = 0 to Output
ACK = 0 to Output Float
WR = 1 to OBF = 0
ACK = 0 to OBF = 1
STB = 0 to IBF = 1
RD = 1 to IBF = 0
RD = 0 to INTR = 0
STB = 1 to INTR = 1
ACK = 1 to INTR = 1
WR = 0 to INTR = 0
A
0
0
1
1
pulse can be 500ns Min.
WR
RD
A
Parameter
0
1
0
0
t
RV
t
HV
RD
0
0
0
t
RV
specified)
WR
A
t
RV
1
1
1
Input Operation (READ)
Symbol
t
t
t
t
WOB
t
t
t
t
t
t
t
t
t
t
t
AOB
t
WIT
t
RIB
WB
SIB
RIT
SIT
AIT
HR
PH
AD
KD
AK
ST
PS
IR
CS
0
0
0
C
C
C
C
C
C
L
L
L
L
L
L
PORT A → Data Bus
PORT B → Data Bus
PORT C → Data Bus
CC
= 150pF
= 150pF
= 50pF
= 15pF
= 150pF
= 150pf, Note 8
Test Conditions
SS
Min
300
350
150
20
−
0
0
0
−
−
−
−
−
−
−
−
−
−
Typ
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
Max Unit
350
300
250
300
350
300
300
400
300
350
450
−
−
−
−
−
−
−
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns