MPC563XM Reference Manual, Rev. 1
832
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
Using the TDL1, TDL2, MRL1 and MRL2 conditions, the microcode can easily resolve the state, in a
similar manner as m2_st, with additional information on the second transition (TDL2).
Both Match Request, Single Transition (bm_st)
On an input signal, this is a double timeout mechanism on two different time bases. Both match
recognitions must occur before the signal transition to generate a match timeout service request. Assertion
of TDL1 blocks both match1 and match2 recognitions, and captures both time bases, indicating there was
no double timeout condition from both time bases.
Using the same timebase implements two timeout conditions, the first only sets its related MRL and the
second generates a service request. Using these flags allows the microcode to check if one or both match
recognitions precede the signal transition.
Both Match Request, Double Transition (bm_dt)
In this mode the first transition detection does not block matches, since both match recognitions are
required to generate a match service request. The second transition detection asserts TDL2, blocks match1
and match2, captures its related timebase and generates transition service request. In this mode, a Match1
recognition which occurs after the assertion of TDL1 does not capture a new value in Capture1, to preserve
the actual signal transition time. Assertion of TDL1, however, always captures its related timebase.
This mode allows putting a double match timeout condition on the second transition. Typically, a pulse
trailing edge timing can be checked against two time bases, to indicate if the pulse has not ended when
both MRL1 and MRL2 are asserted. When a transition service request is generated by TDL2 assertion, the
state of MRL1 and MRL2 indicates which timeout condition occurred, if any.
Ordered Mode with Match2 Request, Single Transition (m2_o_st)
On an input channel, this mode provides a closing window filter for a single signal transition. Match1
assertion captures its programmed time base in Capture1, opens the filter window (enables assertion of
TDL1), and enables assertion of MRL2. Match2 recognition captures its related timebase, closes the
window (disables assertion of TDL1) and generates a service request. Due to Match1 and Match2
ordering, the window is opened for at least one microcycle. Match2 recognition indicates a window
timeout condition which blocks late signal transitions, outside the prediction window. Transition detection
blocks both matches, indicating the transition occurred inside the estimated window. Transitions can be
detected from the microcycle following MRL1 assertion until the microcycle on which MRL2 is asserted.
When TDL1 is asserted inside the window range it disables both matches, captures both time bases and
generates a transition service request.
Using this mode, the channel can replace software window filtering of qualified transitions with the
channel hardware window. The window opening and closing time can be scheduled for any of the two time
bases or a combination of them.
Ordered Mode with Match2 Request, Double Transition (m2_o_dt)
In this mode the channel logic implements a window filter for two detected signal transitions. MRL1
assertion captures its related timebase and enables the assertion of both TDL1 and TDL2. MRL2 assertion
captures its related timebase and disables the assertion of both TDL1 and TDL2. Transitions can be