mc9s08sc4 Freescale Semiconductor, Inc, mc9s08sc4 Datasheet - Page 22

• Manufacturer Part Number: mc9s08sc4
• Description: Mc9s08sc4 8-bit Microcontroller Data Sheet
• Manufacturer: Freescale Semiconductor, Inc

Chapter 3 Electrical Characteristics
3.11.2
Synchronizer circuits determine the shortest input pulses that can be recognized or the fastest clock that can be used as the
optional external source to the timer counter. These synchronizers operate from the current bus rate clock.
22
2
3
4
5
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. Refer to
When any reset is initiated, internal circuitry drives the reset pin low for about 66 cycles of t
frequency changes to the untrimmed DCO frequency (f
to 0, and there is an extra divide-by-two because BDIV is reset to 0:1. After other resets trim stays at the pre-reset value.
This is the minimum pulse width that is 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.
Timing is shown with respect to 20% V
Num
1
2
3
4
5
TPM Module Timing
RESET PIN
—
—
—
—
—
C
External clock frequency
External clock period
External clock high time
External clock low time
Input capture pulse width
MC9S08SC4 MCU Series Data Sheet, Rev. 4
Rating
DD
and 80% V
Table 3-13. TPM Input Timing
Figure 3-9. Reset Timing
DD
Figure
reset
levels. Temperature range –40°C to 125°C.
= (f
t
extrst
3-9.
dco_ut
Symbol
t
t
f
t
TCLKH
f
TCLKL
ICPW
TEXT
TEXT
)/4) because TRIM is reset to 0x80 and FTRIM is reset
Min
1.5
1.5
1.5
dc
4
cyc
. After POR reset the bus clock
1/4 f
Max
Freescale Semiconductor
—
—
—
—
op
MHz
Unit
t
t
t
t
CYC
CYC
CYC
CYC