Command Considerations › Expression Components › User Symbols

User Symbols

Additional Work Areas

User symbols identify storage areas set aside by the debugger as additional work areas. Each user symbol must be prefaced by a colon (:). The user symbols and their meanings are:

• :DRn for a debugger general register, where n represents the number of the register and can have a value of 0 through 15
• :DREGS for all debugger registers
• :H1 and :H2 for halfword 1 and halfword 2
• :F1 and :F2 for fullword 1 and fullword 2
• :UCHR for a 48-byte character area

  You can also refer to specified sections of this area:

  • :UC0, the first 16 bytes
  • :UC16, the next 16 bytes
  • :UC32, the last 16 bytes

Examples

The example below illustrates one way in which you can use the work areas as a debugging aid. In this example, when the program being debugged has reached a breakpoint and the debugger facility is in control, you can copy the current values in program registers to registers in the debugger work area. For instance, to save the contents of all 16 of the general registers of the program, issue this command:

set :dregs = :regs

To save the contents of a single register, copy the values currently in the user register to a debugger register, with a command in this format:

set :dr1 = :r1

Later in the debugger session, the user register previously saved can be restored with this command:

set :r1 = :dr1

Contents Remain for Session

You can modify or refer to the values in these registers at any time during a debugger session; debugger register contents remain only for the duration of the current session.

For more detailed information on the use of the SET command, see Debugger Commands.