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

PRELIMINARY DATA
WP channel type OA 147
1.12.3 Data match registers
The DM provides a single data value/data mask comparator (controlled by
additional DM.OA_MATCH_* registers) which is used to provide additional filtering of
OA channels.
The standard ACTION_EXCEPTION, ACTION_ECOUNT, ACTION_CHAIN_ALTER and
PRE_CHAIN_CLEAR (as specified by WPC.WP_OAX_ACTION) apply as normal and are
totally unaffected by the programming of these additional DM.OA_MATCH_*
registers.
The debug module’s data value/data mask comparator can be combined with one, or
several of the standard OA channels. This allows an additional set of actions to be
performed:
• Trace data can be made conditional on the data value written matching a
specified value/mask.
This is determined by the oa_match field of DM.WP_OAX_ACTION.
• A debug interrupt can be generated, which is triggered whenever a specified OA
channel triggers, and the DM data value/mask comparison also triggers.
This is determined by the action_interrupt field of DM.WP_OAX_ACTION but
differs from the standard DEBUGOA exception (specified by the action_exception
field of WPC.WP_OAX_ACTION) as follows:
- It generates an interrupt rather than an exception.
Interrupts are asynchronous to the instruction stream, and thus do not occur
precisely;
- As it is a DEBUGINT event, it uses offset 0x200 to RESVEC/DBRVEC;
- The TEA register does not contain the data address.
- The interrupt is distinguished from other causes of debug interrupt, by
DM.EXP_CAUSE.OA_MATCH_INTERRUPT == 1.
D R A FT
05-SA-10003 v1.0
SuperH, Inc.
SH-5 System Architecture, Volume 3: Debug