GR740-UM-DS, Nov 2017, Version 1.7
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GR740
33.6.9 AHB trace buffer filter control register
Table 532.
0x000048 - ATBFC - AHB trace buffer filter control register
33.6.10 AHB trace buffer filter mask register
Table 533.
0x00004C - ATBFM - AHB trace buffer filter mask register
33.6.11 AHB trace buffer breakpoint registers
The DSU contains two breakpoint registers for matching AHB addresses. A breakpoint hit is used to
freeze the trace buffer by automatically clearing the enable bit. Freezing can be delayed by program-
ming the DCNT field in the trace buffer control register to a non-zero value. In this case, the DCNT
value will be decremented for each additional trace until it reaches zero, after which the trace buffer is
frozen. A mask register is associated with each breakpoint, allowing breaking on a block of addresses.
31
14 13 12 11 10
9
8
7
4
3
2
1
0
RESERVED
WPF
R
BPF
RESERVED
PF AF FR FW
0
0
0
0
0
0
0
0
0
r
rw
r
rw
r
rw rw rw rw
31: 14
RESERVED
13: 12
AHB watchpoint filtering (WPF) - Bit 13 of this field applies to AHB watchpoint 2 and bit 12
applies to AHB watchpoint 1. If the WPF bit for a watchpoint is set to ‘1’ then the watchpoint will
not trigger unless the access also passes through the filter. This functionality can be used to, for
example, set a AHB watchpoint that only triggers if a specified master performs an access to a spec-
ified slave.
11: 10
RESERVED
9: 8
AHB breakpoint filtering (BPF) - Bit 9 of this field applies to AHB breakpoint 2 and bit 8 applies to
AHB breakpoint 1. If the BPF bit for a breakpoint is set to ‘1’ then the breakpoint will not trigger
unless the access also passes through the filter. This functionality can be used to, for instance, set a
AHB breakpoint that only triggers if a specified master performs an access to a specified slave. Note
that if a AHB breakpoint is coupled with an AHB watchpoint then the setting of the corresponding
bit in this field has no effect.
7: 4
RESERVED
3
Performance counter Filter (PF) - If this bit is set to ‘1’, the cores performance counter (statistical)
outputs will be filtered using the same filter settings as used for the trace buffer. If a filter inhibits a
write to the trace buffer, setting this bit to ‘1’ will cause the same filter setting to inhibit the pulse on
the statistical output.
2
Address Filter (AF) - If this bit is set to ‘1’, only the address range defined by AHB trace buffer
breakpoint 2’s address and mask will be included in the trace buffer.
1
Filter Reads (FR) - If this bit is set to ‘1’, read accesses will not be included in the trace buffer.
0
Filter Writes (FW) - If this bit is set to ‘1’, write accesses will not be included in the trace buffer.
31
16 15
0
SMASK[15:0]
MMASK[15:0]
0
0
rw
rw
31: 16
Slave Mask (SMASK) - If SMASK[n] is set to ‘1’, the trace buffer will not save accesses performed
to slave n. Note that this field has more bits than there are slaves connected to the Processor AHB
bus.
15: 0
Master Mask (MMASK) - If MMASK[n] is set to ‘1’, the trace buffer will not save accesses per-
formed by master n. Note that this field has more bits than there are masters connected to the Proces-
sor AHB bus.
