L32I — Load 32-bit

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
L32I 0010 0010
t 3210
s 3210
imm8 76543210

Assembler Syntax

L32I at, as, 0..1020

C Syntax

#include <xtensa/tie/xt_core.h>

extern int XT_L32I(const int * p, immediate i);

Description

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

L32I is a 32-bit load from memory. It forms a virtual address by adding the contents of address register as and an 8-bit zero-extended constant value encoded in the instruction word shifted left by two. Therefore, the offset can specify multiples of four from zero to 1020. Thirty-two bits (four bytes) are read from the physical address. This data is then written to address register at.

If the Region Translation Option or the MMU Option is enabled, the virtual address is translated to the physical address. If not, the physical address is identical to the virtual address. If the translation or memory reference encounters an error (for example, protection violation, non-existent memory), the processor raises one of several exceptions .

Without the Unaligned Exception Option , the two least significant bits of the address are ignored. A reference to an address that is not 0 mod 4 produces the same result as a reference to the address with the least significant bits cleared. With the Unaligned Exception Option, such an access raises an exception.

If the Instruction Memory Access Option is configured, L32I is one of only a few memory reference instructions that can access instruction RAM/ROM.

Operation

vAddr ← AR[s] + (022||imm8||02)
(mem32, error) ← Load32(vAddr)
if error then
	EXCVADDR ← vAddr
	Exception (LoadStoreErrorCause)
else
	AR[t] ← mem32
endif

Exceptions

Memory Load Group (see Memory Load Group:)

Protos that use L32I

proto L32I { out int32 r, in const int32 * p, in immediate i }{}{
L32I r, p, i + 0;
}
proto uint32_loadi { out uint32 c, in const uint32 * p, in immediate o }{}{
L32I c, p, o + 0;
}