
Timers
DSP56303 Technical Data, Rev. 11
Freescale Semiconductor
1-15
1.11 Timers
The DSP56303 has three identical and independent timers. Each timer can use internal or external clocking and can
either interrupt the DSP56303 after a specified number of events (clocks) or signal an external device after
counting a specific number of internal events.
Table 1-15.
Triple Timer Signals
Signal Name
Type
State During
Reset1,2
Signal Description
TIO0
Input or Output
Ignored Input
Timer 0 Schmitt-Trigger Input/Output— When Timer 0 functions as an
external event counter or in measurement mode, TIO0 is used as input. When
Timer 0 functions in watchdog, timer, or pulse modulation mode, TIO0 is used
as output.
The default mode after reset is GPIO input. TIO0 can be changed to output or
configured as a timer I/O through the Timer 0 Control/Status Register (TCSR0).
TIO1
Input or Output
Ignored Input
Timer 1 Schmitt-Trigger Input/Output— When Timer 1 functions as an
external event counter or in measurement mode, TIO1 is used as input. When
Timer 1 functions in watchdog, timer, or pulse modulation mode, TIO1 is used
as output.
The default mode after reset is GPIO input. TIO1 can be changed to output or
configured as a timer I/O through the Timer 1 Control/Status Register (TCSR1).
TIO2
Input or Output
Ignored Input
Timer 2 Schmitt-Trigger Input/Output— When Timer 2 functions as an
external event counter or in measurement mode, TIO2 is used as input. When
Timer 2 functions in watchdog, timer, or pulse modulation mode, TIO2 is used
as output.
The default mode after reset is GPIO input. TIO2 can be changed to output or
configured as a timer I/O through the Timer 2 Control/Status Register (TCSR2).
Notes:
1.
In the Stop state, the signal maintains the last state as follows:
If the last state is input, the signal is an ignored input.
If the last state is output, the signal is tri-stated.
2.
The Wait processing state does not affect the signal state.
3.
All inputs are 5 V tolerant.