Motorola DSP56309 User Manual page 268

Note: In this mode, internal logic preserves the TIO value and direction for an
additional 2.5 internal clock cycles after a DSP56309 hardware RESET signal is
asserted. This insures that a valid reset signal is generated when the TIO signal
is used to reset the DSP56309.
9.4.5 Reserved Modes
Modes 8, 11, 12, 13, 14, and 15 are reserved.
9.4.6 Special Cases
The following special cases apply during wait and stop state.
9.4.6.1 Timer Behavior during Wait
Timer clocks are active during the execution of the WAIT instruction and timer activity
is undisturbed. If a timer interrupt is generated, the DSP56309 leaves the wait state and
services the interrupt.
9.4.6.2 Timer Behavior during Stop
During the execution of the STOP instruction, the timer clocks are disabled, timer
activity is stopped, and the TIO signals are disconnected. Any external changes that
happen to the TIO signals are ignored when the DSP56309 is in the stop state. To insure
correct operation, the timers should be disabled before the DSP56309 is placed into the
stop state.
9.4.7 DMA Trigger
Each timer can also be used to trigger DMA transfers. For this to occur, a DMA channel
must be programmed to be triggered by a timer event. The timer issues a DMA trigger
on every event in all modes of operation. The DMA channel does not have the capability
to save multiple DMA triggers generated by the timer. To insure that all DMA triggers
are serviced, the user must provide for the preceding DMA trigger to be serviced before
the next trigger is received by the DMA channel.
MOTOROLA DSP56309UM/D
Triple Timer Module
Timer Operational Modes
9-27