SMJ34020A Datasheet, PDF (68/92 Pages) Texas Instruments – GRAPHICS SYSTEM PROCESSOR

SMJ34020A
GRAPHICS SYSTEM PROCESSOR
SGUS011B – APRIL 1991 – REVISED AUGUST 1995
local-bus timing: output clocks (see Note 4 and Figure 34)
SMJ34020A-32
’34020A-40
NO.
UNIT
MIN
MAX
MIN
MAX
11 tc(LCK)
Cycle time, period of local clocks LCLK1, LCLK2 4tc(CKI)†+ s
4tc(CKI) + s^†
ns
12 tw(LCKH)
Pulse duration, local clock high
2tQ – 15
2tQ – 13.5
ns
12a tw(LCKH)
Pulse duration, LCLK1 high (see Note 5)
2tQ – 10
2tQ –7
ns
13 tw(LCKL)
Pulse duration, local clock low
2tQ – 15+ s
2tQ – 13.5 + s
ns
13a tw(LCKL)
Pulse duration, LCLK1 low (see Note 5)
2tQ–10+ s
2tQ –7 + s
ns
14 tt(LCK)
Transition time, LCLK1 or LCLK2
15
13.5 ns
15 th(CK1H-CK2L) Hold time, LCLK2 low after LCLK1 high
tQ – 15
tQ – 13.5
ns
16 th(CK2H-CK1H) Hold time, LCLK1 high after LCLK2 high
tQ – 15
tQ – 13.5
ns
17 th(CK1L-CK2H) Hold time, LCLK2 high after LCLK1 low
tQ – 15
tQ – 13.5
ns
18 th(CK2L-CK1L) Hold time, LCLK1 low after LCLK2 low
tQ – 15+ s
tQ – 13.5 + s
ns
19 th(CK1H-CK2H) Hold time, LCLK2 high after LCLK1 high
3tQ – 15
3tQ – 13.5
ns
20 th(CK2H-CK1L) Hold time, LCLK1 low after LCLK2 high
3tQ – 15+ s
3tQ – 13.5 + s
ns
21 th(CK1L-CK2L) Hold time, LCLK2 low after LCLK1 low
3tQ – 15+ s
3tQ – 13.5 + s
ns
22 th(CK2L-CK1H) Hold time, LCLK1 high after LCLK2 low
3tQ – 15+ s
3tQ – 13.5 + s
ns
† _{This is a functional minimum and is not tested. This parameter can also be specified as 4tQ.}
NOTES: 4. s = tQ if using the clock stretch;
s = 0 otherwise
5. Parameters 12a and 13a are specified with 1.5 V timing levels (parameters 12 and 13 are specified with standard timing voltage
levels).
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1 Q2
11
14
12
14
13
LCLK1
LCLK2
19
20
15
16
14
17
14
12a
13a
21
22
18
11
12
13
NOTE A: Although LCLK1 and LCLK2 are derived from CLKIN, no timing relationship between CLKIN and the local clocks is to be assumed,
except the period of the local clocks is four times the period of CLKIN.
Figure 34. Local-Bus Timing: Output Clocks
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