SYSTIM capture/compare events:
- SYSTIM event output:
- One event output per
channel + one combined event output for all the channels routed to the
Event Manager.
- Total of 2 event outputs.
Only the combined event has a standard complement of MIS/RIS/IMASK/
ISET/ICLR/IMCLR/IMSET registers. RIS is automatically cleared when
reading capture value or writing compare value.
- The combined
event also includes a timer overflow event. This event is
asserted when time overflows and remain asserted till 4sec.
- The event set within RIS can be cleared via ICLR, and also when any of
the following occurs:
- Reading from the capture register (this only occurs if the
channel is in capture mode or disarmed).
- Writing to the compare register.
- Arming the channel in capture mode via writing CH n CFG.MODE bit
to 1.
- Arming the
channel in capture mode via writing ARMSET n bit to 1, provided
CH n CFG.MODE bit as 0.
- Trigger past event
- A compare event
triggers immediately if 0 <= TIME-CMP < 2^22, in other
words if the compare time is now or up to 1.048576s in the past
for channel 0 (configured to 250 ns resolution), and up to
4.294s in the past for channel 1 (configured to 1 µs).
- SYSTIM event inputs:
- One event input per channel.
- Can be configured to capture on a configurable condition (rising edge,
falling edge and both edges). This also generates a capture event output
on the same channel, setting the RIS interrupt flag.
- Event input needs to be
defined in the Event Manager by writing to SOC_AON.TMEVTCTL[5:0] SYSTIM0
bit field for SYSTIM channel 0 or SOC_AON.TMEVTCTL[13:8] SYSTIM1 bit
field for SYSTIM channel 1.
- The SYSTIM.CHnCFG[2:1] INP bit field can be used to configure the
capture condition.
- If SYSTIM.CHnCFG[2:1] INP bit field = 0 then capture on the
rising edge.
- If SYSTIM.CHnCFG[2:1] INP bit field = 1 then capture on the
falling edge.
- If SYSTIM.CHnCFG[2:1] INP bit field = 2 then capture on both
rising and falling edges.
- Software must arm a channel for capture, and a capture event
automatically disarms the channel.