Information

phase A
phase B
FTM counter
increment/decrement
FTM counter
MOD
CNTIN
0x0000
Time
set TOF
clear TOFDIR
-1
set TOF
clear TOFDIR
-1
-1
-1
-1
-1
-1
-1
-1
-1-1
-1
-1
-1
-1
-1-1
-1
-1
-1
-1
-1
-1
-1
-1
Figure 35-213. FTM counter overflow in down counting for Quadrature Decoder mode
35.4.25.1 Quadrature Decoder boundary conditions
The following figures show the FTM counter responding to motor jittering typical in
motor position control applications.
phase A
phase B
FTM counter
MOD
CNTIN
0x0000
Time
Figure 35-214. Motor position jittering in a mid count value
The following figure shows motor jittering produced by the phase B and A pulses
respectively:
Chapter 35 FlexTimer Module (FTM)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 811