LDF

From NDWiki
Jump to: navigation, search
LDF
Description Load floating accumulator
Format LDF <addr. mode> <disp.>
Code 034 0008
Affected T:=(ea) A=(ea+1) D=(ea+2)
Type User
Architecture ND-100, ND-110

LDF is an assembly instruction. The contents of the effective address and the two following locations ared loaded into the floating accumulator, i.e. T, A and D registers. The instruction always load the three registers, even in CPUs with the 32-bit floating point option. With 32-bit floating point units the application must use the LDD doubleword instruction instead of LDF. MAC programmers may use the MAC mnemonic LDR instead, which will translate to LDF or LDD depending on target.

LDF is also used as a generic 3-word load function, and applications may use LDF with STF to copy 3 words at the time with no floating point operation performed on the floating point accumulator. This usage is independent of which floating point option the CPU is equipped with.

References