WS82C55A
0 C to 70oC
o
AC Electrical Specifications
V
= +5V± 10%, GND = 0V; T =
CC
A
WS82C55A*5
WS-XX82C55A
TEST
SYMBOL
READ TIMING
(1) tAR
PARAMETER
MIN
MAX
MAX
UNITS
CONDITIONS
MIN
ns
ns
Address Stable Before RD
Address Stable After RD
RD Pulse Width
0
0
-
-
0
-
(2) tRA
0
150
-
-
(3) tRR
250
-
-
ns
ns
ns
ns
-
120
(4) tRD
Data Valid From RD
200
75
-
1
2
(5) tDF
Data Float After RD
10
300
10
75
-
(6) tRV
Time Between RDs and/or WRs
300
0
WRITE TIMING
(7) tAW
Address Stable Before WR
Address Stable After WR
WR Pulse Width
0
-
-
-
-
-
-
-
ns
(8) tWA
20
ns
ns
20
(9) tWW
100
100
30
100
100
30
-
-
(10) tDW
(11) tWD
OTHER TIMING
(12) tWB
(13) tIR
Data Valid to WR High
Data Valid After WR High
ns
ns
-
350
WR = 1 to Output
-
350
-
ns
-
1
0
-
Peripheral Data Before RD
Peripheral Data After RD
ACK Pulse Width
0
ns
ns
(14) tHR
(15) tAK
0
-
0
-
-
200
-
200
100
ns
ns
ns
-
(16) tST
STB Pulse Width
100
-
(17) tPS
Peripheral Data Before STB High
Peripheral Data After STB High
ACK = 0 to Output
20
-
20
50
-
-
(18) tPH
(19) tAD
(20) tKD
(21) tWOB
(22) tAOB
(23) tSIB
(24) tRIB
(25) tRIT
(26) tSIT
(27) tAIT
(28) tWIT
(29) tRES
50
-
ns
ns
-
-
175
250
150
150
150
150
200
150
150
200
-
175
250
1
2
ACK = 1 to Output Float
WR = 1 to OBF = 0
20
20
-
ns
ns
ns
-
150
150
1
1
ACK = 0 to OBF = 1
STB = 0 to IBF = 1
-
-
-
-
150
150
ns
1
1
RD = 1 to IBF = 0
-
-
-
ns
ns
RD = 0 to INTR = 0
-
200
150
150
200
-
1
STB = 1 to INTR = 1
ACK = 1 to INTR = 1
WR = 0 to INTR = 0
Reset Pulse Width
-
ns
ns
-
1
-
-
1
1
-
-
ns
ns
500
500
1,(Note)
NOTE: Period of initial Reset pulse after power-on must be at least 50µsec. Subsequent Reset pulses may be 500ns minimum.
18
Wing Shing [ WING SHING COMPUTER COMPONENTS ]
