MPC563XM Reference Manual, Rev. 1
920
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
stop request=1). When the eTPU is idle: stop request prevails over Service Request if there is not a
hardware breakpoint request; a hardware breakpoint request leads to debug mode immediately if there is
no Service Request, and after TST if there is Service Request (regardless of stop requests). The rules above
are summarized in the
, showing the destination state of the microengine in each situation.
When a thread is ending, it goes to Idle or TST only if there is neither a hardware breakpoint request (signal
ndedi_thread_break negated) nor a request to stop (MDIS=1 or SoC stop request=1). When thread is
ending and there are simultaneous hardware breakpoint (ndedi_thread_break active) and stop (MDIS=1 or
SoC stop request=1) requests, hardware breakpoint prevails and the engine enters Debug mode (Halt_idle
state).
If the engine entered Debug mode after a thread finished (Halt_idle state) and a “go” command comes from
the debug interface, the engine state machine goes to Idle and the rules above apply. It means that if a “go”
is issued in Halt_idle state with MDIS=1, the engine goes to Idle for one microcycle and then stops (if
MDIS or SoC stop request keeps asserted and there is no other breakpoint request).
NOTE
Hardware breakpoint requests are ignored for the first microinstruction
executed when microengine leaves halt.
23.4.10.2.4
Hardware Watchpoints
Debug Interface allows watchpoints on the same conditions available for hardware breakpoints (see
Section 23.4.10.2.3, “Hardware Breakpoints
23.4.10.2.5
Software Breakpoints
A software breakpoint occurs when microengine executes a HALT microinstruction. Any number of
software breakpoints can be set in code, usually replacing an active microinstruction.
Like any other microinstruction, HALT increments the PC and pre-fetches the next instruction. So, before
the halt state is suspended, if the original program flow must be followed, the original instruction at the
Table 23-100. Breakpoint, Stop and Service Requests resolution from Idle
Breakpoint
Request
MDIS
Service
Request
Final State
no
0
0
Idle
no
1
0
Stop
no
0
1
TST
no
1
1
Stop
Yes
0
0
Halt_idle
Yes
1
0
Halt_idle
Yes
0
1
TST
1
1
breaks after TST, if signal ndedi_sync_break is still
asserted (see the debug interface specification in
the eTPU Integration Guide).
Yes
1
1
TST