Compaq ECQD2KCTE manual Load Memory Data into Integer Register, Ldl

Models: ECQD2KCTE

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4.2.2 Load Memory Data into Integer Register

Format:

LDxRa.wq,disp.ab(Rb.ab)!Memory format

Operation:

va {Rbv + SEXT(disp)}

 

CASE

 

big_endian_data: va’ va XOR 0002

!LDQ

big_endian_data: va’ va XOR 1002

!LDL

big_endian_data: va’ va XOR 1102

!LDWU

big_endian_data: va’ va XOR 1112

!LDBU

little_endian_data: va’ va

 

ENDCASE

 

Ra (va’)<63:0>

!LDQ

Ra SEXT((va’)<31:0>)

!LDL

Ra ZEXT((va’)<15:0>)

!LDWU

Ra ZEXT((va’)<07:0>)

!LDBU

Exceptions:

Access Violation

Alignment

Fault on Read

Translation Not Valid

Instruction mnemonics:

LDBU

Load Zero-Extended Byte from Memory to Register

LDL

Load Sign-Extended Longword from Memory to Register

LDQ

Load Quadword from Memory to Register

LDWU

Load Zero-Extended Word from Memory to Register

Qualifiers:

None

Description:

The virtual address is computed by adding register Rb to the sign-extended 16-bit displace- ment. For a big-endian access, the indicated bits are inverted, and any memory management fault is reported for va (not va).

4–6Alpha Architecture Handbook

Page 62
Image 62
Compaq ECQD2KCTE manual Load Memory Data into Integer Register, Ldl