Datasheet

Electrical Characteristics
MCF51AC256 ColdFire Microcontroller Data Sheet, Rev.7
Freescale Semiconductor 35
2.11.2 Timer (TPM/FTM) 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.
Figure 13. Timer External Clock
Figure 14. Timer Input Capture Pulse
2.11.3 MSCAN
Table 18. TPM/FTM Input Timing
NUM C Function Symbol Min Max Unit
1—
External clock frequency
f
TPMext
DC
f
Bus
/4
MHz
2—
External clock period
t
TPMext
4—
t
cyc
3D
External clock high time
t
clkh
1.5 —
t
cyc
4D
External clock low time
t
clkl
1.5 —
t
cyc
5D
Input capture pulse width
t
ICPW
1.5 —
t
cyc
Table 19. MSCAN Wake-Up Pulse Characteristics
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 MSCAN wake-up dominant pulse filtered t
WUP
—— 2s
2 D MSCAN wake-up dominant pulse pass t
WUP
5—5s
t
TPMext
t
clkh
t
clkl
TPMxCLK
t
ICPW
TPMxCHn
t
ICPW
TPMxCHn