DSP56303 FREESCALE [Freescale Semiconductor, Inc], DSP56303 Datasheet - Page 208

• Manufacturer Part Number: DSP56303
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Triple Timer Module
9.3.3 Pulse Width Modulation
In Mode 7, the timer generates periodic pulses of a preset width. When the counter equals the
value in the TCPR, the
counter are placed into the TCR. If the TCSR[TCIE] bit is set, a compare interrupt is generated.
The counter continues to increment on each timer clock.
If counter overflow occurs, the
interrupt is generated if the TCSR[TOIE] bit is set. If the TCSR[TRM] bit is set, the counter is
loaded with the TLR value on the next timer clock and the count resumes. If the TCSR[TRM] bit
is cleared, the counter continues to increment on each timer clock. This process repeats until the
timer is disabled.
When the TCSR[TE] bit is set and the counter starts, the
each subsequent toggle of the
the INV bit is set, the
TIO
The value of the TLR determines the output period ($FFFFFF − TLR + 1). The timer counter
increments the initial TLR value and toggles the
$FFFFFF. The duty cycle of the
value in the TLR increments to a value equal to the value in the TCPR, the
The duty cycle is equal to ($FFFFFF – TCPR) divided by ($FFFFFF − TLR + 1). For a 50
percent duty cycle, the value of TCPR is equal to ($FFFFFF + TLR + 1)/2.
Note:
9-16
TC3
0
signal generates the following signal: 0101.
TC2
Bit Settings
The value in TCPR must be greater than the value in TLR.
1
TC1
1
TIO
TIO
TC0
signal generates the following signal: 1010. If the INV bit is cleared, the
1
output signal is toggled and TCSR[TCF] is set. The contents of the
TIO
TIO
TIO
Mode
signal, the polarity of the
7
DSP56303 User’s Manual, Rev. 2
output signal is toggled, TCSR[TOF] is set, and an overflow
signal is determined by the value in the TCPR. When the
Pulse width modulation
TIO
Name
signal when the counter value exceeds
Mode Characteristics
TIO
TIO
signal assumes the value of INV. On
signal is reversed. For example, if
Function
PWM
TIO
Output
Freescale Semiconductor
TIO
signal is toggled.
Internal
Clock