IBM PPC440X5 Computer Hardware User Manual


 
lswi
Load String Word Immediate
Preliminary PPC440x5 CPU Core User’s Manual
instrset.fm.
September 12, 2002 Page 335 of 589
lswi
Load String Word Immediate
EA (RA|0)
if NB = 0 then
CNT
32
else
CNT
NB
n
CNT
R
FINAL
((RT + CEIL(CNT/4) – 1) % 32)
r
RT 1
i
0
do while n > 0
if i = 0 then
r
r+1
if r = 32 then
r
0
GPR(r))
0
GPR(r)
i:i+7
) MS(EA,1)
i
i+8
if i = 32 then
i
0
EA
EA + 1
n
n–1
An effective address (EA) is determined by the RA field. If the RA field contains 0, the EA is 0. Otherwise, the
EA is the contents of register RA.
The NB field specifies the byte count CNT. If the NB field contains 0, the byte count is CNT = 32. Otherwise,
the byte count is CNT = NB.
A series of CNT consecutive bytes in main storage, starting at the EA, are loaded into CEIL(CNT/4) consecu-
tive GPRs, four bytes per GPR, until the byte count is exhausted. Bytes are loaded into GPRs; the byte at the
lowest address is loaded into the most significant byte. Bits to the right of the last byte loaded into the last
GPR are set to 0.
The set of loaded GPRs starts at register RT, continues consecutively through GPR(31), and wraps to
register 0, loading until the byte count is exhausted, which occurs in register R
FINAL
.
If instruction bit 31 contains 1, the contents of CR[CR0] are undefined.
Registers Altered
RT and subsequent GPRs as described above.
Invalid Instruction Forms
Reserved fields
lswi RT, RA, NB
31 RT RA NB 597
0 6 11 16 21 31