DS87C550 Datasheet, PDF (38/50 Pages) Dallas Semiconductor – EPROM High-Speed Micro with A/D and PWM

DS87C550
§ All signals characterized with load capacitance of 80 pF except Port 0, ALE, PSEN , RD and WR
with 100 pF.
§ Interfacing to memory devices with float times (turn off times) over 25 ns may cause contention. This
will not damage the parts, but will cause an increase in operating current.
§ Specifications assume a 50% duty cycle for the oscillator. Port 2 and ALE timing will change in
relation to duty cycle variation.
MOVX CHARACTERISTICS
PARAMETER
SYMBOL
VARIABLE CLOCK
MIN
MAX
Data Access ALE
Pulse Width
Address Hold after
ALE Low for
MOVX Write
RD Pulse Width
WR Pulse Width
RD Low to
Valid Data In
Data Hold
after Read
Data Float
after Read
ALE Low to
Valid Data In
Port 0 Address
to Valid Data In
Port 2 Address
to Valid Data In
ALE Low to RD
or WR Low
Port 0 Address to
RD or WR Low
Port 2 Address to
RD or WR Low
Data Valid to
WR Transition
t_LHLL2
t_LLAX2
t_RLRH
t_WLWH
t_RLDV
t_RHDX
t_RHDZ
t_LLDV
t_AVDV1
t_AVDV2
t_LLWL
t_AVWL1
t_AVWL2
t_QVWX
0.375t_MCS-5
0.5t_MCS-5
1.5t_MCS-10
0.125t_MCS-5
0.25t_MCS-5
1.25t_MCS-10
0.5t_MCS-5
C_ST*t_MCS-10
0.5t_MCS-5
C_ST*t_MCS-10
0
0.125t_MCS-5
0.25t_MCS-5
1.25t_MCS-10
0.25t_MCS-5
0.5t_MCS-5
2.5t_MCS-10
0.375t_MCS-5
0.625t_MCS-5
2.625t_MCS-10
-5
0.5t_MCS-20
C_ST*t_MCS-20
0.25t_MCS-5
0.5t_MCS-5
1.5t_MCS-15
0.625t_MCS-20
(C_ST+0.25)*t_MCS-40
(C_ST+1.25)*t_MCS-40
0.75t_MCS-20
(C_ST+0.375)*t_MCS-20
(C_ST+1.375)*t_MCS-20
0.875t_MCS-20
(C_ST+0.5)*t_MCS-20
(C_ST+1.5)*t_MCS-20
1.25t_MCS+5
0.25t_MCS+5
1.25t_MCS+10
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
STRETCH
VALUES C_ST
(MD2:0)
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=7
C_ST=0
1<=C_ST<=7
C_ST=0
1<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
C_ST=0
1<=C_ST<=3
4<=C_ST<=7
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