DocID025202 Rev 7
RM0365
Debug support (DBG)
1066
33.14.2 Debug support for timers, watchdog, bxCAN and I
2
C
During a breakpoint, it is necessary to choose how the counter of timers and watchdog
should behave:
•
They can continue to count inside a breakpoint. This is usually required when a PWM is
controlling a motor, for example.
•
They can stop to count inside a breakpoint. This is required for watchdog purposes.
For the bxCAN, the user can choose to block the update of the receive register during a
breakpoint.
For the I
2
C, the user can choose to block the SMBUS timeout during a breakpoint.
For timers having complementary outputs, when the counter is stopped
(DBG_TIMx_STOP=1), the outputs are disabled (as if the MOE bit was reset) for safety
purposes.
33.14.3 Debug
MCU
configuration register
This register allows the configuration of the MCU under DEBUG. This concerns:
•
Low-power mode support
•
Timer and watchdog counter support
•
bxCAN communication support
•
Trace pin assignment
This DBGMCU_CR is mapped on the External PPB bus at address 0xE0042004.
It is asynchronously reset by the PORESET (and not the system reset). It can be written by
the debugger under system reset.
If the debugger host does not support these features, it is still possible for the user software
to write to these registers.
DBGMCU_CR
Address: 0xE004 2004
Only 32-bit access supported
POR Reset: 0x0000 0000 (not reset by system reset)
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Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
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1
0
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Res
Res
Res
Res
Res
Res
Res
TRACE_
MODE
[1:0]
TRACE
_
IOEN
Res.
Res
DBG_
STAND
BY
DBG_
STOP
DBG_
SLEEP
rw
rw
rw
rw
rw
rw