MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
817
Preliminary—Subject to Change Without Notice
transition1 is initially blocked and IPAC1 is programmed to detect such “transitions”, the occurrence of a
Match1 only unblocks the transition after the sampling. It means that the transition on the first Match
(IPAC1 configurations 100 and 101) is not effective on predefined modes where transition 1 is enabled by
Match 1 (m2_st, m2_dt, m2_o_st and m2_o_dt) or user-defined modes with UDCM bit M1ET asserted. A
transition 1 can still happen after the match 1, however, if Match1 register is reprogrammed without
clearing MRL1.
TDL1/2 assertion conditions initiates a capture event of one or both selected TCR buses. TDL1 or TDL2
transition event generates a Service Request, depending on channel mode, previous events and the state of
SRI. For more information on service request scheme refer to
Section 23.4.1.1.2, “Entry Point Address
Section 23.4.5.4, “Channel Modes
.”
Assertion of TDL1/2 occurs on either T2 or T4 positive edges. The capture event occurs on the same clock,
and captures the time base value present when TDL1/2 was asserted
. TDL1 and TDL2 are negated during
reset and may also be negated independently by microcode. TDL1/2 is reset by no way other than reset
and microcode.
It is the transition from 0 to 1 in TDL that causes the Transition actions: even if TDL assert conditions are
satisfied, no action due to a Transition occurs if TDL was already set to 1. However, if a Transition and a
microoperation negating TDLs occur at the same time and TDL was already negated, TDL negation by
microcode overrides its assertion, but any dependable captures and pin action occurs anyway.
23.4.5.3.2
TCCE1 - Transition Continous Capture Enable
TCCE1 enables capture from transitions after the TDL1 flag is set. TCCE1 is negated on reset, so that a
capture occurs only when TDL1 asserts. TCCE1 can be set and reset by microcode only, through the
instruction field MTD (see
Section 23.4.9.3.8, “Disable Match and Transition Service Requests
only be set together with inhibiting of the channel service requests (SRI = 1)
1
.
When TCCE1 is asserted, the transition events specified by IPAC1 that occur after TDL1 is set also cause
captures into the Capture 1 register only. However, output actions related to transition events are still
blocked by TDL1.
23.4.5.4
Channel Modes
The Enhanced Channels support various modes of operation combining Match1/2 recognition and
transition detection events which set MRL1/2 and TDL1/2. The channel mode is individually set for each
channel by eTPU microcode, through the PDCM register (see
Section , “PDCM - Predefined Channel
). The PDCM register selects among a set of 13 predefined channel modes, and also a user-defined
channel mode.
The order in which events occur, combined with assigned channel mode, establish which following event
detections are inhibited and/or enabled, as well as the actions taken: Time Base capture, flag setting
(MRL1/2, TDL1/2), match disabling (MRLE1/2), output signal transition, and Service Request. Those
channel mode characteristics are fixed in the predefined modes, but can be individually programmed in
the user-defined channel mode.
1.TCCE1 provides compatibility with TPU when service request is inhibited.