ROTW — Rotate Window

Instruction Word

Slot
Inst
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
9876543210
Format x24 - 24 bit(s) 0
ROTW 0100000010000000 0000
mn 3210

Assembler Syntax

ROTW -8..7

C Syntax

#include <xtensa/tie/xt_regwin.h>

extern void XT_ROTW(immediate simm4);

Description

(please consult the Xtensa ® Instruction Set Architecture Reference Manual for any cross references and additional information)

ROTW adds a constant to WindowBase, thereby moving the current window into the register file. ROTW is intended for use in exception handlers and context switch code.

ROTW is a privileged instruction.

Operation

if CRING != 0 then
	Exception (PrivilegedCause)
else
	WindowBase ← WindowBase + imm4
endif

Exceptions

EveryInst Group (see EveryInst Group:)GenExcep(PrivilegedCause) if Exception Option

Implementation Pipeline

In Out
WindowBase Rstage WindowBase Rstage

Protos that use ROTW

proto ROTW { in immediate simm4 }{}{
ROTW simm4 + 0;
}