JTAG Watchpoints dialog box

The J-Link/J-Trace driver and a supported device.

Selects how the defined watchpoints will be used. Choose between:

Normal	Uses the two watchpoints individually (OR).
Range	Combines both watchpoints to cover a range where watchpoint 0 defines the start of the range and watchpoint 1 the end of the range. Selectable ranges are restricted to being powers of 2.
Chain	Makes a trigger of watchpoint 1 and watchpoint 0. A program break will then occur when watchpoint 0 is triggered.

Specify the address to watch for.

Value	Specify an address or a C-SPY expression that evaluates to an address. Alternatively, you can select an address you have previously watched for from the drop-down list. For detailed information about C-SPY expressions, see C-SPY expressions.
Mask	Qualifies each bit in the value. A zero bit in the mask will cause the corresponding bit in the value to be ignored in the comparison. To match any address, enter 0. Note that the mask values are inverted with respect to the notation used in the Arm hardware manuals.
Address Bus Pattern	Shows the bit pattern to be used by the address comparator. Ignored bits as specified in the mask are shown as `x`.

Selects the access type of the data to watch for:

Any	Matches any access type.
OP Fetch	Matches an operation code (instruction) fetch.
Read	Reads from location.
Write	Writes to location.
R/W	Reads from or writes to location.

Specifies the data to watch for. For size, choose between:

Any Size	Matches data accesses of any size.
Byte	Matches byte size accesses.
Halfword	Matches halfword size accesses.
Word	Matches word size accesses.

You can specify a value to watch for. Choose between:

Value	Specify a value or a C-SPY expression. Alternatively, you can select a value you have previously watched for from the drop-down list. For detailed information about C-SPY expressions, see C-SPY expressions.
Mask	Qualifies each bit in the value. A zero bit in the mask will cause the corresponding bit in the value to be ignored in the comparison. To match any address, enter 0. Note that the mask values are inverted with respect to the notation used in the Arm hardware manuals.
Data Bus Pattern	Shows the bit pattern to be used by the address comparator. Ignored bits as specified in the mask are shown as `x`.

Defines the state of the external input. Choose between:

Selects which CPU mode that must be active for a match. Choose between:

User	Selects the CPU mode USER.
Non User	Selects one of the CPU modes SYSTEM SVC, UND, ABORT, IRQ, or FIQ.
Any	Ignores the CPU mode.

IAR Embedded Workbench for Arm 9.70.x