HP 3000 III Series Manual page 65

System/CPU Overview
Table 2-5. Condition Codes
1--·-------
----~---
-.- ----.--- - ---_._._-- --------.-----.------- - - -------- --
I
CCA sets CC
=
CCG (OO) if operand> 0
I
CCL (Ol) if operand
<
0
I
CCE (lO) if operand
=
0
I
CCB sets CC
=
CCG (OO) if numerical (%060 - 071)
CCL (Ol) if special character (all
other octal values)
CCE (10) if alphabetic (uppercase,
%101 - 132; lowercase, %141 -
172)
CCC sets CC
=
CCG (OO) if operand 1 > 2
CCL (Ol) if operand 1
<
2
CCE (10) if operand 1
=
2
I CCD sets CC
=
CCG (OO) if device is not ready
CCL (Ol) if non-responding Device
Controller
CCE (10) if respond ing Device
Controller and/or external
device is ready
Notes: CC
=
Condition Code
CCG
=
Condition Code Greater
CCL
=
Condition Code Less
CCE
=
Condition Code Equal
__.
~
._-_._. .__. _ . ._,,__
._~_,_.
. . _ . __._._, . .
_ ~
.,_._. ._. . . _ _. . . _.__..
~._:.
v_. .
The most common condition code pattern is pattern A (CCA). In
CCA, the cond ition code is se t to 00 if the operand is grea te r
than zero; to 01 if the operand is less than zero; and to 10 if
the operand is exactly zero.
Condition code pattern B (CCB) is used with byte or iented
instructions. In CCB,
the condition code is set to 00 if the
operand byte is an ASCII numerical character which would be
represented by octal values 060 through 071. The code is set to
10 if the byte is an ASCII alphabetic character which would be
represented by octal values 101 through 132 for upper-case
letters and 141 through 172 for lower-case letters. The code is
set to
01 if the byte is an ASCII special character which would
be represented by the remaining octal values.
Condition code pattern C (CCC) is used with comparison instruc-
tions. In CCC, the condition code
is set to 00 if operand 1 is
greater than operand 2; to 01 if operand 1 is less
than operand
2; and to 10 if operand 1 is equal to operand 2.
2-33