AE_DB — discard bits from the head of the input bit stream (count in AR register)

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
AE_DB 011101110100 0100
s 3210
t 3210

Assembler Syntax

AE_DB a0..15(ars), a0..15(art)

C Syntax

#include <xtensa/tie/xt_hifi2.h>

extern void AE_DB(const unsigned short * a /*inout*/, unsigned count);

Description

AE_DB discards bits from the head of the input bit stream, refreshing AE_BITHEAD state from address (a + 2) if necessary. a points to the current bit stream head address in memory, and a0 contains the number of bits to discard, which must lie in the range [0..16]. If a load from memory takes place to refresh the AE_BITHEAD state, a is advanced by 2 so it will refer automatically to the next 16-bit chunk of the bit stream.

Implementation Pipeline

In Out
AE_BITPTR Mstage, AE_BITHEAD Mstage, ars Estage, art Mstage AE_BITPTR Mstage, AE_BITHEAD Mstage, ars Mstage

Protos that use AE_DB

proto AE_DB { inout const uint16 * a, in uint32 count }{}{
AE_DB a, count;
}