EXTW — External Wait

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
EXTW 000000000010000011010000

Assembler Syntax

EXTW

C Syntax

#include <xtensa/tie/xt_core.h>

extern void XT_EXTW(void);

Description

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

EXTW is a superset of MEMW. EXTW ensures that both

complete (or perform as described in ) before either

is allowed to begin.

While MEMW is intended to implement the volatile attribute of languages such as C and C++, EXTW is intended to be an ordering guarantee for all external effects that the processor can have, including processor pins defined in TIE.

Because the instruction execution pipeline is implementation-specific, the operation section below specifies only a call to the implementation's extw function.

Operation

extw

Exceptions

EveryInst Group (see EveryInst Group:)

Protos that use EXTW

proto EXTW { }{}{
EXTW;
}