SuperH (SH) 64-bit RISC Series SH-5 System Architecture, Volume ...

PRELIMINARY DATA
96 Debug module
Since the chain-latch can be directly set by one WPC watchpoint hit and directly
cleared by a different WPC watchpoint hit, the trigger-out pin can be used to
accurately measure the time between different WPC watchpoint events.
4 The trigger-out pin is connected to the output of the DM.CHAIN_0 chain-latch.
Since the chain-latch can be directly set by one WPC or bus analyzer watchpoint
hit and directly cleared by a different watchpoint hit, the trigger-out pin can be
used to measure the time between different watchpoint events. There are two
main differences between this TRIGGER-OUT function and the one described above
for the WPC.CHAIN_0 chain-latch:
• The DM.CHAIN_0 chain latch can be set or cleared by any bus analyzer or WPC
watchpoint.
• The action logic for DM.CHAIN_0 chain-latch setting/clearing is located at the
output of the capture buffer. If stall-mode is selected, the chain-latch setting/
clearing action will be delayed by an unpredictable amount of time as the
capture buffer fills. If discard-mode is selected, watchpoint hit events will be
discarded when the capture buffer fills and expected chain-latch setting/
clearing actions may not occur.
5 If stall mode is selected, the trigger-out pin goes low during the time that the
CPU is stalled. This allows external equipment connected to the trigger-out pin
to observe CPU stall behavior.
D R A FT
SuperH, Inc.
SH-5 System Architecture, Volume 3: Debug 05-SA-10003 v1.0