NonStop S-Series Server Description Manual (G06.24+)

TNS Instruction Set
HP NonStop S-Series Server Description Manual—520331-003
11-26
Definitions of TNS Instructions
LAND (000010). Logical AND A With B. A and B are logically ANDed. The two words
are deleted from the stack and the result pushed on. Condition Code is set. (For an
example, see Figure 11-5 on page 11-6.)
LBA (000364). Load Byte via A. The unsigned byte contained in the effective memory
location pointed to by the byte address in A is loaded onto the stack, with zero
extension, replacing the prior contents of A. LBA accesses the current data segment
only. The Condition Code is set on the category of the loaded byte in A: CCL indicates
ASCII numeric, CCE indicates ASCII alphabetic, and CCG indicates special ASCII
character.
LBAS (000354). Load Byte via A From System. The unsigned byte contained in the
effective memory location pointed to by the byte address in A is loaded onto the stack,
with zero extension, replacing the prior contents of A. A refers to an address in the
system data segment. The Condition Code is set on the category of the loaded byte in
A: CCL indicates ASCII numeric, CCE indicates ASCII alphabetic, and CCG indicates
special ASCII character.
LBP (-2-4--). Load Byte From Program (Current Code Segment) Into A. The contents
of the P-relative byte address that is computed as a function of displacement (a signed
8-bit value), and optionally indexing and indirection, are pushed onto the register stack.
The high-order byte is set to zero. The addressing range is half a segment. For direct
addressing, if the P register currently indicates an address in the upper half of the code
segment (bit 0 of P = 1), %100000 is added to the computed address, so that the
address will always be relative to whichever half of the segment P currently indicates.
For indirect addressing, the address is based on the indirect cell’s half segment, not
the half segment that contains the LBP instruction. The Condition Code is set on the
category of the loaded byte in A: CCL indicates ASCII numeric, CCE indicates ASCII
alphabetic, and CCG indicates special ASCII character. Figure 11-10 on page 11-27
illustrates the addressing operations for the LBP instruction, assuming addresses in
the first half of the code segment. For binary coding details, refer to Table B-1 on
page B-1.
The first example of LBP instruction addressing shown in Figure 11-10
is direct, using
a negative displacement value and an index value of 17. The second example is
indirect and uses a positive displacement.