TC1796
Peripheral Units (Vol. 2 of 2)
General Purpose Timer Array (GPTA)
User’s Manual
24-86
V2.0, 2007-07
GPTA, V2.0
24.2.3.5 LTC Application Examples
This section describes a PWM generation example using Local Timer Cells.
Fully Programmable PWM Signal Generation with 5 LTCs
, a logical unit of five LTCs can be used to generate a PWM
signal with a programmable duty cycle, period length, and fully coherent update of the
period and duty cycle. In this example, LTC00 up to LTC04 are used to produce a PWM
signal at the output of LTC04.
Figure 24-58 PWM Signal Generation with LTCs (Full Coherent Update)
LTC00 is configured in Reset Timer Mode thus providing all subsequent cells with a time
base. LTC00 is clocked by a clock signal at the LTC00IN which has been selected by the
LTC input multiplexer.
LTC01 and LTC02 are configured in Compare Mode. They are enabled if its SI inputs
are at low level and responsible for the LTC04OUT signal generation in Phase 1. With
the programmed values from
, the LTC04OUT signal of Phase 1 has a period
of 1000
D
(= 3E8
H
) clocks of the LTC00IN clock signal and a duty cycle of 20% (= 200
D
or C8
H
).
Local Timer Cell LTC00
M1I M0I
TI
EO
SI
M1O
TI
EI
SO
YI
YO
Local Timer Cell LTC01
M1I M0I
LTC00IN
TI
EO
SI
M1O
TO
EI
SO
YI
YO
MCA05967
LTC04OUT
Reset
Timer
Period
Compare
Local Timer Cell LTC02
M1I M0I
TI
EO
SI
M1O
TO
EI
SO
YI
YO
Duty Cycle
Compare
Local Timer Cell LTC03
M1I M0I
TI
EO
SI
M1O
TO
EI
SO
YI
YO
Period
Compare
Local Timer Cell LTC04
M1I M0I
TI
EO
SI
M1O
TO
EI
SO
YI
YO
Duty Cycle
Compare
M0O
M0O
M0O
M0O
M0O