Slot Inst16b | 6 3 | 6 2 | 6 1 | 6 0 | 5 9 | 5 8 | 5 7 | 5 6 | 5 5 | 5 4 | 5 3 | 5 2 | 5 1 | 5 0 | 4 9 | 4 8 | 4 7 | 4 6 | 4 5 | 4 4 | 4 3 | 4 2 | 4 1 | 4 0 | 3 9 | 3 8 | 3 7 | 3 6 | 3 5 | 3 4 | 3 3 | 3 2 | 3 1 | 3 0 | 2 9 | 2 8 | 2 7 | 2 6 | 2 5 | 2 4 | 2 3 | 2 2 | 2 1 | 2 0 | 1 9 | 1 8 | 1 7 | 1 6 | 1 5 | 1 4 | 1 3 | 1 2 | 1 1 | 1 0 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Format x16b - 16 bit(s) | 1 | 1 | 0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
RETW.N | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
s | 3 | 2 | 1 | 0 |
RETW.N
(please consult the Xtensa ® Instruction Set Architecture Reference Manual for any cross references and additional information)
RETW.N
is the same as RETW
in a 16-bit encoding.
n ← AR[0]31..30 nextPC ← PC31..30||AR[0]29..0 owb ← WindowBase m ← if WindowStartWindowBase-4'b0001 then 2'b01 elsif WindowStartWindowBase-4'b0010 then 2'b10 elsif WindowStartWindowBase-4'b0011 then 2'b11 else 2'b00 if n=2'b00 | (m!=2'b00 & m!=n) | PS.WOE=0 | PS.EXCM=1 then -- undefined operation -- may raise illegal instruction exception else WindowBase ← WindowBase − (02||n) if WindowStartWindowBase != 0 then WindowStartowb ← 0 else -- Underflow exception PS.EXCM ← 1 EPC[1] ← PC PS.OWB ← owb nextPC ← if n = 2'b01 then WindowUnderflow4 else if n = 2'b10 then WindowUnderflow8 else WindowUnderflow12 endif PS.CALLINC ← n -- in some implementations endif
In | Out |
---|---|
WindowBase Rstage , WindowStart Rstage ,
PSEXCM Rstage , PSWOE Rstage , ars Estage
|
WindowBase Estage , WindowStart Estage ,
PSCALLINC Estage
|