External Clock
Table 23-4 and figure 23-7 show the input conditions for the external clock.
Table 23-4 External Clock Input Conditions
Item
External clock input low
pulse width
External clock input
high pulse width
External clock rise time t
External clock fall time
Clock low pulse
width level
Clock high pulse width
level
EXTAL
848
V
= 3.0 V
CC
to 3.6 V,
PV
= 3.0 V
CC
to 5.5 V
Symbol
Min
t
20
EXL
t
20
EXH
—
EXr
t
—
EXf
t
0.4
CL
80
t
0.4
CH
80
t
EXH
t
EXr
Figure 23-7 External Clock Input Timing
V
= 3.0 V
CC
to 3.6 V
PV
= 5.0 V
CC
±10%
Max
Min
Max
—
15
—
—
15
—
10
—
5
10
—
5
0.6
0.4
0.6
—
80
—
0.6
0.4
0.6
—
80
—
t
EXL
t
EXf
Unit
Test Conditions
ns
Figure 23-7
ns
ns
ns
ø ≥ 5 MHz Figure
t
cyc
ns
ø < 5 MHz
ø ≥ 5 MHz
t
cyc
ns
ø < 5 MHz
× 0.5
V
CC
25-2