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GR716-DS-UM, May 2019, Version 1.29
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GR716
timer enable bit in the AHB trace buffer control register is set), and restarted when execution is
resumed.
The value is used as time tag in the instruction and AHB trace buffer.
19.7.6 DSU ASI register
The DSU can perform diagnostic accesses to different ASI areas. The value in the ASI diagnostic
access register is used as ASI while the address is supplied from the DSU.
19.7.7 AHB Trace buffer control register
The AHB trace buffer is controlled by the AHB trace buffer control register:
Table 145.
0x000008 - DTTC - DSU time tag counter
31
0
TIMETAG
0
rw
31: 0
DSU Time Tag Value (TIMETAG)
Table 146.
0x400024 - DASI - ASI diagnostic access register
31
8
7
0
RESERVED
ASI
0
NR
r
rw
31: 8
RESERVED
7: 0
ASI (ASI) - ASI to be used on diagnostic ASI access
Table 147.
0x000040 - ATBC - AHB trace buffer control register
31
16 15
8
7
6
5
4
3
2
1
0
DCNT
RESERVED
DF SF TE TF
BW
BR DM EN
0
0
0
0
0
0
0
0
0
0
rw
r
rw rw rw rw
r
rw rw rw
31: 16
Trace buffer delay counter (DCNT)
15: 8
RESERVED
7
Sample Force (SF) - If this bit is written to ‘1’ it will have the same effect on the AHB trace buffer as
if HREADY was asserted on the bus at the same time as a sequential or non-sequential transfer is
made. This means that setting this bit to ‘1’ will cause the values in the trace buffer’s sample regis-
ters to be written into the trace buffer, and new values will be sampled into the registers. This bit will
automatically be cleared after one clock cycle.
Writing to the trace buffer still requires that the trace buffer is enabled (EN bit set to ‘1’) and that the
CPU is not in debug mode or that tracing is forced (TF bit set to ‘1’). This functionality is primarily
of interest when the trace buffer is tracing a separate bus and the traced bus appears to have frozen.
6
Timer enable (TE) - Activates time tag counter also in debug mode.
5
Trace force (TF) - Activates trace buffer also in debug mode. Note that the trace buffer must be disa-
bled when reading out trace buffer data via the core’s register interface.
4: 3
Bus width (BW) - This value corresponds to log2(Supported bus width / 32)
2
Break (BR) - If set, the processor will be put in debug mode when AHB trace buffer stops due to
AHB breakpoint hit.
1
Delay counter mode (DM) - Indicates that the trace buffer is in delay counter mode.
0
Trace enable (EN) - Enables the trace buffer.