STH/sth (Store Halfword)

Store Halfword D-form
sth RS,D(RA)
if RA = 0 then b .. 0
else b .. (RA)
EA .. b + EXTS(D)
MEM(EA, 2) .. (RS)48:63
Let the effective address (EA) be the sum (RA|0)+ D.
(RS)48:63 are stored into the halfword in storage
addressed by EA.
Special Registers Altered:
None