Symbol Technologies CMOS CXP854P60 User Manual
Page 12
– 12 –
CXP854P60
AC Characteristics
(1) Clock timing
∗
t
sys indicates one of three values according to the contents of the clock control register. (For CPU clock
selection.)
t
sys (ns) = 2000/fc (Upper 2 bits = "00"), 4000/fc (Upper 2 bits = "01"), 16000/fc (Upper 2 bits = "11")
System clock frequency
System clock input
pulse width
System clock
rise and fall times
Event counter input
clock pulse widtth
Event counter input clock
rise and fall times
f
C
t
XL
,
t
XH
t
CR
,
t
CF
t
EH
,
t
EL
t
ER
,
t
EF
XTAL
EXTAL
EXTAL
EXTAL
EC
EC
MHz
ns
ns
ns
ms
Item
System
Pin
Condition
Min.
Max.
Unit
Fig. 1, Fig. 2
Fig. 1, Fig. 2
External clock drive
Fig 1, Fig 2
External clock drive
Fig. 3
Fig. 3
3.5
50
t
sys + 50
∗
9
200
20
(Ta = –10 to +75°C, V
DD
= 4.5 to 5.5V, Vss = 0V)
Fig. 1. Clock timing
EXTAL
t
XH
t
XL
t
CF
t
CR
0.4V
V
DD
– 0.4V
1/fc
Fig. 2. Clock applied condition
Crystal oscillator
Ceramic oscillator
EXTAL
XTAL
External clock
EXTAL
XTAL
OPEN
C
1
C
2
Fig. 3. Event count clock timing
EC
t
EH
t
EL
t
EF
t
ER
0.2V
DD
0.8V
DD