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

PRELIMINARY DATA
Debug module 107
1.8.11 DM.TRBUF (trace buffer register)
This register is specified in Table 32. Fields in this register are used only when
debug software allocates a portion of target system memory space as a trace buffer.
DM.TRBUF
0x100048
Field Bits Size Volatile? Synopsis Type
TR_MODE [1:0] 2 — Trace Buffer mode selection RW
Operation
When read
When written
HARD reset 0
Defines the mode of operation of the trace buffer in the target
system’s memory.
The value in this field is only significant if DM.TRCTL.DESTN = 0b10
(that is, the trace destination is programmed as trace buffer mode).
Value - Description
0b00: Trace buffer disabled. This allows debug software to disable
tracing whilst the other fields (such as TR_SIZE and TR_BASE) are
programmed.
0b01: “Circular trace buffer” mode. The trace buffer acts as a
wrap-around buffer with the newest trace entry overwriting the
oldest.
0b10: “Trace buffer hold” mode. The trace buffer acts as a fixed
length buffer. DM.TRCTL.STALL_MODE (see Section 1.8.10: on
page 97 effects the behavior (see Section : Stall/discard overview
on page 91).
0b11: Undefined
Returns current value
Updates current value.
Undefined behavior may result if this field is changed whilst a trace
message is being written to memory. Software should disable all
watchpoint channel actions that could produce trace messages and
wait long enough to allow any pending messages to drain to
memory. The time to wait is implementation-dependent.
D R A FT
Table 32: DM.TRBUF definition
05-SA-10003 v1.0
SuperH, Inc.
SH-5 System Architecture, Volume 3: Debug