head 1.1; branch 1.1.1; access ; symbols noReleaseTag:1.1.1.1 noVendorName:1.1.1; locks ; strict; comment @# @; 1.1 date 2003.02.10.04.04.54; author doru; state Exp; branches 1.1.1.1; next ; 1.1.1.1 date 2003.02.10.04.04.54; author doru; state Exp; branches ; next ; desc @@ 1.1 log @Initial revision @ text @ ALU Main Page Modules Related Pages

ALU
[Hardware resources]

ALU connectivity:

Here it can be seen how the ALU plugs into the pipeline.

The ALU is a 100% combinational device.
It accepts 2 operands:

a 16 bit operand
This is taken through the Bypass Unit.
an 8 bit operand
This is taken through the Bypass Unit.

The ALU output is 16 bits wide.

ALU opcodes:

NOP
OP1
Transfers operand 1 directly to the ALU output.
OP2
Transfers operand 2 directly to the lower 8 bits of ALU output.
ADD8
ADC8
Adds with carry lower 8 bits of operand 1 with operand 2.
SUB8
SBC8
AND8
EOR8
OR8
INC8
DEC8
COM8
NEG8
SWAP8
LSR8
ASR8
ROR8
ADD16
Adds without carry operand 1 with operand 2 sign extended to 16 bits.
SUB16
MUL8
MULS8
MULSU8
FMUL8
FMULS8
FMULSU8

ALU flags:

H (half carry)
S (sign)
V (two's complement)
N (negative)
Z (zero)
C (carry)

Generated on Tue Dec 31 20:26:30 2002 for Pipelined AVR microcontroller by

1.2.16

@ 1.1.1.1 log @Importing into repository the new directory structure. @ text @@

ALU [Hardware resources]

ALU
[Hardware resources]