Information

then the generated signal is not available on channel (j)
output.
• If CHjIE = 1, then the channel (j) interrupt is generated
when the channel (j) match occurs.
• At the intermediate load neither the channels outputs nor
the FTM counter are changed. Software must set the
intermediate load at a safe point in time.
• The intermediate load feature must be used only in
Combine mode.
35.4.28 Global time base (GTB)
The global time base (GTB) is a FTM function that allows the synchronization of
multiple FTM modules on a chip. The following figure shows an example of the GTB
feature used to synchronize two FTM modules. In this case, the FTM A and B channels
can behave as if just one FTM module was used, that is, a global time base.
GTBEOUT bit
gtb_in
gtb_out
gtb_in
example glue logic
FTM module B
FTM module A
GTBEEN bit
FTM counter
enable logic
FTM counter
enable
gtb_out
Figure 35-217. Global time base (GTB) block diagram
The GTB functionality is implemented by the GTBEEN and GTBEOUT bits in the
CONF register, the internal input signal gtb_in, and the internal output signal gtb_out.
The GTBEEN bit enables gtb_in to control the FTM counter enable signal:
• If GTBEEN = 0, each one of FTM modules works independently according to their
configured mode.
• If GTBEEN = 1, the FTM counter update is enabled only when gtb_in is 1.
In the configuration described in the preceding figure, FTM modules A and B have their
FTM counters enabled if at least one of the gtb_out signals from one of the FTM modules
is 1. There are several possible configurations for the interconnection of the gtb_in and
Chapter 35 FlexTimer Module (FTM)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 815