12
CXP854P60
AC Characteristics
(1) Clock timing
tsys indicates one of three values according to the contents of the clock control register. (For CPU clock
selection.)
tsys (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
fC
tXL,
tXH
tCR,
tCF
tEH,
tEL
tER,
tEF
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
tsys + 50
9
200
20
(Ta = 10 to +75°C, VDD = 4.5 to 5.5V, Vss = 0V)
Fig. 1. Clock timing
EXTAL
tXH tXLtCF tCR
0.4V
VDD 0.4V
1/fc
Fig. 2. Clock applied condition
Crystal oscillator
Ceramic oscillator
EXTAL XTAL
External clock
EXTAL XTAL
OPEN
C1C2
Fig. 3. Event count clock timing
EC
tEH tELtEF tER
0.2VDD
0.8VDD