Debug Manual

Debug Command Overview
Debug Manual—421921-003
3-11
Expression Syntax
If a command requires a 16-bit expression, the evaluated expression must be
represented in 16 bits. A syntax error occurs if the evaluated expression cannot be
represented in 16 bits.
If the command allows a 32-bit expression, the evaluated expression is always 32
bits long, with the sign extended into the high-order word. However, when a 32-bit
word expression is displayed with the = command, it is always shown as a 16-bit
word value if it can be expressed in 16-bit word.
•
The default numeric base in expressions is octal, except for the DN command and
N address mode, where the default base is hexadecimal.
•
The BASE command overrides the default numeric base.
•
In a value notation of the form number.number, the notation for the numeric base
of the input value is not required in both halves of the value notation. For example,
suppose that you are entering a decimal value but the default base is octal: the
base notation # is required only in the first half of the value, but it is allowed in both
halves. Both of these forms are equivalent:
#8.#823
#8.823
Examples
Expression
#27
'AB'
'A'
4*3+2
4*(3+2)
177777/2
-(177777/2)
-1
-1.0
2.1000
(2.1000)<<1
%h23
%h8009.3000
%h8009.%h3000
$T8 ! Contents of TNS/R register $T8
$PC+4 ! Contents of TNS/R register $PC plus 4
R1 ! Contents of TNS register 1
L-2 ! Contents of TNS register L minus 2
R1.R0 ! Contents of TNS registers 0 and 1
175,07,00068-D L+3 ! Display L+3 (that is, display contents
000003: %000033 ! of word addressed by the sum of the
! contents of TNS register L plus 3)