Open Core Protocol Debug Interface Specification rev 1.0 - OCP-IP

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number. This will be 0 or 1, depending on the trigger that is in question. If any one or more of
these conditions is true, then the trigger should be 0.
Each TAP trigger signals are qualified by PISTAPENABLED and PISDOMAINPOWERED
for the respective TAP. These are all combined as shown in Figure B.1. If any of the qualified
trigger signals from the TAPs is set and nTRST is not being asserted, the Trigger signal is
driven low. This signal drives both the active low output enable, POEMU0OEN and the data
output signal, POEMU0ON. The tristate buffer shown shaded is implemented outside of the C-
TRIG Module.
ntrst
pidomainpowered(0)
pitapenabled(0)
piemu0o(0)
piemu0oz(0)
pidomainpowered(1)
pitapenabled(1)
piemu0o(1)
piemu0oz(1)
trigger0_n
poemu0on
poemu0oen
EMU0
pidomainpowered(N-1)
pitapenabled(N-1)
piemu0o(N-1)
piemu0oz(N-1)
Figure B.1: Trigger Generation
If less TAPs are instantiated in the debug bank in the implementation of C-TRIG than inputs
are defined, not all of the contributing trigger equations list above will exist. Trigger inputs
only exists for TAPs that exist. This doesn't apply in case of a OCP distributed implementation
where just the desired TAPs will be implemented.
The PISDOMAINPOWERED[m] and PISTAPENABLED[m] signals are used in the trigger
builder equations.
If triggers are originated from different power domains, appropriate level shifters must be
implemented external to the C-TRIG trigger generation block.
B.4.3.3 Trigger Input
The value of each trigger input is driven out to each core via the POEMUxIm signals, where x
is the trigger number and m is the module TAP number. Hence, a signal is driven for each
instantiated secondary TAP, regardless of whether the TAP is selected. In a C-TRIG
implementation with 16 TAPs, 16 signals are always driven with the current value of the
trigger.
Triggers to the cores can be created from the external trigger input signal, PIEMUxI or from
the trigger output signal, Triggerx_N. If either of these two signals is low a trigger may be
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