GR740-UM-DS, Nov 2017, Version 1.7
402
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GR740
33.6.13 AHB watchpoint control register
The DSU has two AHB watchpoints that can be used to freeze the AHB tracebuffer, or put the proces-
sor in debug mode, when a specified data pattern occurs on the AMBA bus. These watchpoints can
also be coupled with the two AHB breakpoints so that a watchpoint will not trigger unless the AHB
breakpoint is triggered. This also means that when a watchpoint is coupled with an AHB breakpoint,
the breakpoint will not cause an AHB tracebuffer freeze, or put the processor(s), in debug mode
unless also the watchpoint is triggered.
The bus data lines are taken through a register stage before being compared with the watch-
point registers in the DSU. Data watchpoints have one extra cycle of latency compared to a
AHB breakpoint due to this pipelining.
Table 537.
0x000080 - AHBWPC - AHB watchpoint control register
31
7
6
5
4
3
2
1
0
RESERVED
IN CP EN R
IN CP EN
0
0
0
0
0
0
0
0
r
rw rw rw
r
rw rw rw
31: 7
RESERVED
6
Invert (IN) - Invert AHB watchpoint 2. If this bit is set the watchpoint will trigger if data on the AHB
bus does NOT match the specified data pattern (typically only usable if the watchpoint has been cou-
pled with an address by setting the CP field).
5
Couple (CP) - Couple AHB watchpoint 2 with AHB breakpoint 1
4
Enable (EN) - Enable AHB watchpoint 2
3
RESERVED
2
Invert (IN) - Invert AHB watchpoint 1. If this bit is set the watchpoint will trigger if data on the AHB
bus does NOT match the specified data pattern (typically only usable if the watchpoint has been cou-
pled with an address by setting the CP field).
1
Couple (CP) - Couple AHB watchpoint 1 with AHB breakpoint 1
0
Enable (EN) - Enable AHB watchpoint 1