Maxim-integrated MAXQ622 Manual do Utilizador descarregar pdf (Página 232)

MAXQ612/MAXQ622 User’s Guide

16-22 Maxim Integrated

SLA/SLA2/SLA4

Shift Accumulator Left Arithmetically One, Two, or Four Times

Description:

Shifts the active accumulator left once, twice, or four times respectively for SLA, SLA2, and SLA4.

For each shift iteration, a 0 is shifted into the lsbit and the msbit is shifted into the Carry (C) flag. For

signed data, this shifting process effectively retains the sign orientation of the data to the point at

which overflow/underflow would occur.

Status Flags:

C, S, Z

SLA

Carry Flag 15 Active Accumulator (Acc) 0

Operation:

← ← ←

C ← Acc.15; Acc.[15:1] ← Acc.[14:0]; Acc.0 ← 0

Encoding:

1000 1010 0010 1010

Example(s):

; Acc = E345h, C=0, S=1, Z=0

SLA ; Acc = C68Ah, C=1, S=1, Z=0

SLA ; Acc = 8D14h, C=1, S=1, Z=0

SLA2

Carry Flag 15 Active Accumulator (Acc) 0

Operation:

← ← ←

C ← Acc.14; Acc.[15:2] ← Acc.[13:0]; Acc.[1:0] ← 0

Encoding:

1000 1010 0011 1010

Example(s):

; Acc = E345h, C=0, S=1, Z=0

SLA2 ; Acc = 8D14h, C=1, S=1, Z=0

SLA4

Carry Flag 15 Active Accumulator (Acc) 0

Operation:

← ← ←

C ← Acc.12; Acc.[15:4] ← Acc.[11:0]; Acc.[3:0] ← 0

Encoding:

1000 1010 0110 1010

Example(s):

; Acc = E345h, C=0, S=1, Z=0

SLA4 ; Acc = 3450h, C=0, S=0, Z=0

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Maxim-integrated MAXQ622 Manual do Utilizador Página 232