Datasheet

Table Of Contents
Advance Information MC68HC908GP20Rev 2.1
384 Freescale Semiconductor
23.8 5.0-V Control Timing
Characteristic
(1)
1. V
SS
= 0 Vdc; timing shown with respect to 20% V
DD
and 70% V
SS
unless otherwise noted
Symbol Min Max Unit
Frequency of operation
(2)
Crystal option
External clock option
(3)
2. See 23.17 Clock Generation Module Characteristics for more information.
3. No more than 10% duty cycle deviation from 50%
f
osc
32
dc
(4)
4. Some modules may require a minimum frequency greater than dc for proper operation.
See appropriate table for this information.
100
32.8
kHz
MHz
Internal operating frequency f
op
—8.2MHz
Internal clock period (1/f
OP
)t
cyc
122 ns
RESET
input pulse width low
(5)
5. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse
width to cause a reset.
t
IRL
50 ns
IRQ
interrupt pulse width low
(6)
(edge-triggered)
6. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to
be recognized.
t
ILIH
50 ns
IRQ
interrupt pulse period t
ILIL
TBD Note 8 t
cyc
16-bit timer
(7)
Input capture pulse width
Input capture period
7. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to
be recognized.
8. The minimum period, t
ILIL
or t
TLTL
, should not be less than the number of cycles it takes to
execute the interrrupt service routine plus t
cyc
.
t
TH,
t
TL
t
TLTL
TBD
Note 8
ns
t
cyc
Notes: