Datasheet

Electrical Characteristics
MC9S08JS16 Series MCU Data Sheet, Rev. 4
Freescale Semiconductor 19
3.9 AC Characteristics
This section describes AC timing characteristics for each peripheral system.
3.9.1 Control Timing
3
Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum f
BUS
.
Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise
injected into the FLL circuitry via V
DD
and V
SS
and variation in crystal oscillator frequency increase the C
Jitter
percentage for
a given interval.
4
Jitter measurements are based upon a 48 MHz clock frequency.
5
625 ns represents 5 time quanta for CAN applications, under worst case conditions of 8 MHz CAN bus clock, 1 Mbps CAN
bus speed, and 8 time quanta per bit for bit time settings. 5 time quanta is the minimum time between a synchronization edge
and the sample point of a bit using 8 time quanta per bit.
6
Below D
lock
minimum, the MCG is guaranteed to enter lock. Above D
lock
maximum, the MCG will not enter lock. But if the MCG
is already in lock, then the MCG may stay in lock.
7
Below D
unl
minimum, the MCG will not exit lock if already in lock. Above D
unl
maximum, the MCG is guaranteed to exit lock.
Figure 13. Control Timing
Num C Parameter Symbol Min Typical
1
1
Typical values are based on characterization data at V
DD
= 5.0 V, 25 °C unless otherwise stated.
Max Unit
1 D Bus frequency (t
cyc
= 1/f
Bus
)f
Bus
DC — 24 MHz
2 D Internal low-power oscillator period t
LPO
700 — 1300 μs
3D
External reset pulse width
2
(t
cyc
= 1/f
Self_reset
)
2
This is the shortest pulse that is guaranteed to be recognized as a reset pin request. Shorter pulses are not guaranteed to
override reset requests from internal sources.
t
extrst
1.5 × t
Self_reset
——ns
4 D Reset low drive t
rstdrv
66 × t
cyc
——ns
5D
Active background debug mode latch setup
time
t
MSSU
25 — — ns
6D
Active background debug mode latch hold
time
t
MSH
25 — — ns
7D
IRQ pulse width
Asynchronous path
2
Synchronous path
3
3
This is the minimum pulse width guaranteed to pass through the pin synchronization circuitry. Shorter pulses may or may not
be recognized. In stop mode, the synchronizer is bypassed so shorter pulses can be recognized in that case.
t
ILIH,
t
IHIL
100
1.5 × t
cyc
——ns
8D
KBIPx pulse width
Asynchronous path
2
Synchronous path
3
t
ILIH,
t
IHIL
100
1.5 × t
cyc
——ns
9C
Port rise and fall time (load = 50 pF)
4
Slew rate control disabled (PTxSE = 0)
Slew rate control enabled (PTxSE = 1)
4
Timing is shown with respect to 20% V
DD
and 80% V
DD
levels. Temperature range –40°C to 85°C.
t
Rise
, t
Fall
—
—
3
30
—
—
ns