STF

From NDWiki
Jump to: navigation, search
STF
Description Store floating accumulator
Format STF <addr. mode> <disp.>
Code 030 0008
Affected (ea):=T, (ea+1):=A, (ea+2):=D
Type User
Architecture ND-100, ND-110

STF is an assembly instruction. The content of the floating accumulator (T, A and D registers) is stored in three consecutive memory locations starting at effective address. The instruction always stores the three registers, even in CPUs with the 32-bit floating point option. With 32-bit floating point units the application must use the STD doubleword instruction instead of STF. MAC programmers may use the MAC mnemonic STR instead, which will translate to STF or STD depending on target.

STF is also used as a generic 3-word store function, and applications may use STF with LDF 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