The syntax for coding the nominal value is shown in the
subfield format operands in DC instruction.
You must specify the nominal value subfield unless a duplication
value of zero is specified. It defines the value of the constant (or
constants) described and affected by the subfields that precede it.
It is this value that is assembled into the internal binary representation
of the constant. Table 1 shows the formats
for specifying constants.
Table 1. Specifying
constant values| Constant
Type
|
Single
Nominal Value
|
Multiple
Nominal Value
|
Topic No. |
|---|
| C |
'value' |
not allowed |
Character constant—C |
| G |
'<.v.a.l.u.e>' |
not allowed |
Graphic constant—G |
| B
X
H
F
P
Z
E
D
L
|
'value' |
'value,value,...value' |
Binary constant—B
Hexadecimal constant—X
Fixed-point constants—F and H
Fixed-point constants—F and H
Decimal constants—P and Z
Decimal constants—P and Z
Hexadecimal floating-point constants—E, EH, D, DH, L, LH, LQ, Binary floating-point constants—EB, DB, LB
Hexadecimal floating-point constants—E, EH, D, DH, L, LH, LQ, Binary floating-point constants—EB, DB, LB
Hexadecimal floating-point constants—E, EH, D, DH, L, LH, LQ, Binary floating-point constants—EB, DB, LB
|
| A
Y
S
V
R
|
(expression) |
(expression,expression,...expression) |
Address constants
Address constants
Address constants
Address constants
Address constants
|
| Q |
(value) |
(value,value,...value) |
Offset constant—Q |
| J |
(value) |
(value,value,...value) |
Length constant—J |
As the above list shows:
- A data constant value (any type except A, Y, S, Q, J, R, and V)
is enclosed by apostrophes.
- An address constant value (type A, Y, S, V, R) or an offset constant
(type Q) or a length constant (type J) is enclosed by parentheses.
- To specify two or more values in the subfield, the values must
be separated by commas, and the whole sequence of values must be enclosed
by the correct delimiters; that is, apostrophes or parentheses.
- Multiple values are not permitted for character constants.
Spaces are allowed and ignored in nominal values for the quoted
constant types (BDEFHLPXZ). Spaces are significant for C and G constant
types.
How nominal values are specified and interpreted by the assembler
is explained in each of the subsections that follow. There is a subsection
for each of the following types of constant:
- Binary
- Character
- Graphic
- Hexadecimal
- Fixed-Point
- Decimal
- Packed Decimal
- Zoned Decimal
- Address
- Floating-Point
Literal constants are described in Literal constants.