Information

Table 3-46. FTM Instantiations
FTM instance Number of channels Features/usage
FTM0 8 3-phase motor + 2 general purpose or
stepper motor
FTM1 2
1
Quadrature decoder or general purpose
1. Only channels 0 and 1 are available.
Compared with the FTM0 configuration, the FTM1 configuration adds the Quadrature
decoder feature and reduces the number of channels.
3.8.2.2 External Clock Options
By default each FTM is clocked by the internal bus clock (the FTM refers to it as system
clock). Each module contains a register setting that allows the module to be clocked from
an external clock instead. There are two external FTM_CLKINx pins that can be selected
by any FTM module via the SOPT4 register in the SIM module.
3.8.2.3 Fixed frequency clock
The fixed frequency clock for each FTM is MCGFFCLK.
3.8.2.4 FTM Interrupts
The FlexTimer has multiple sources of interrupt. However, these sources are OR'd
together to generate a single interrupt request per FTM module to the interrupt controller.
When an FTM interrupt occurs, read the FTM status registers (FMS, SC, and STATUS)
to determine the exact interrupt source.
3.8.2.5 FTM Fault Detection Inputs
The following fault detection input options for the FTM modules are selected via the
SOPT4 register in the SIM module. The external pin option is selected by default.
• FTM0 FAULT0 = FTM0_FLT0 pin or CMP0 output
• FTM0 FAULT1 = FTM0_FLT1 pin or CMP1 output
• FTM0 FAULT2 = FTM0_FLT2 pin
• FTM0 FAULT3 = FTM0_FLT3 pin
Chapter 3 Chip Configuration
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 105