S9S08SC4E0MTG Datasheet, PDF (22/31 Pages) Freescale Semiconductor, Inc – MC9S08SC4 8-Bit Microcontroller Data Sheet

Chapter 3 Electrical Characteristics
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. Refer to Figure 3-9.
3 _{When any reset is initiated, internal circuitry drives the reset pin low for about 66 cycles of tcyc. After POR reset the bus clock}
frequency changes to the untrimmed DCO frequency (f_reset = (f_{dco_ut})/4) because TRIM is reset to 0x80 and FTRIM is reset
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.
4 _{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.
5 _{Timing is shown with respect to 20% VDD and 80% VDD levels. Temperature range –40°C to 125°C.}
RESET PIN
t_extrst
Figure 3-9. Reset Timing
3.11.2 TPM Module Timing
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.
Table 3-13. TPM Input Timing
Num
1
2
3
4
5
C
Rating
— External clock frequency
— External clock period
— External clock high time
— External clock low time
— Input capture pulse width
Symbol
Min
f_TEXT
dc
t_TEXT
4
t_TCLKH
1.5
t_TCLKL
1.5
f_ICPW
1.5
Max
1/4 f_op
—
—
—
—
Unit
MHz
t_CYC
t_CYC
t_CYC
t_CYC
MC9S08SC4 MCU Series Data Sheet, Rev. 4
22
Freescale Semiconductor