DCSR

nRF54LM20A | nRF54LM20B Datasheet

Address offset: 0x7B0

Debug Control and Status

This register is only accesible from debug mode

Bit number 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
ID F F F F E D C C C B A A
Reset 0x40000003 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1
ID R/W Field Value ID Value Description
A

R

PRV

Privilege level

Contains the privilege level the hart was operating in when Debug Mode was entered. VPR only supports Machine Privilege Level.

MACHINE

3

B

RW

STEP

Step

When set and not in Debug Mode, the hart will only execute a single instruction and then enter Debug Mode. If the instruction does not complete due to an exception, the hart will immediately enter Debug Mode before executing the trap handler, with appropriate exception registers set. The debugger must not change the value of this bit while the hart is running

C

R

CAUSE

Debug Mode enter cause

When there are multiple reasons to enter Debug Mode in a single cycle, hardware should set cause to the cause with the highest priority. Values other than the following are reserved for future use

EBREAK

1

An ebreak instruction was executed. (priority 3)

TRIGGER

2

The Trigger Module caused a breakpoint exception. (priority 4, highest)

HALTREQ

3

The debugger requested entry to Debug Mode using haltreq. (priority 1)

STEP

4

The hart single stepped because step was set. (priority 0, lowest)

RESETHALTREQ

5

The hart halted directly out of reset due to resethaltreq. It is also acceptable to report 3 when this happens. (priority 2)

D

RW

STEPIE

Step Interrupt Enable

The debugger must not change the value of this bit while the hart is running

Disabled

0

Interrupts are disabled during single stepping

Enabled

1

Interrupts are enabled during single stepping. Implementations may hard wire this bit to 0. In that case interrupt behavior can be emulated by the debugger.

E

RW

EBREAKM

M-mode ebreak

SPEC

0

ebreak instructions in M-mode behave as described in the Privileged Spe

ENTERDBG

1

ebreak instructions in M-mode enter Debug Mode

F

R

XDEBUGVER

External Debug version

STDDBG

4

External debug support exists as it is described in this document