SpinAsm XOR and SpinAsm LOG: Difference between pages

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==XOR==
==LOG==
{| class="wikitable"
{| class="wikitable"
|+
|+
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!Instruction coding
!Instruction coding
|-
|-
|XOR
|LOG
|ACC ^ MASK
|<nowiki>C * LOG(|ACC|) + D</nowiki>
|MMMMMMMMMMMMMMMMMMMMMMMM000010000
|CCCCCCCCCCCCCCCCDDDDDDDDDDD01011
|}
|}


======Description======
======Description======
XOR will perform a bit wise "xor" of the current ACC and the 24­bit MASK specified within the instruction word. The instruction will invert ACC provided MASK equals $FFFFFF. (see also the pseudo opcode section)
LOG will multiply the Base2 LOG of the current absolute value in ACC with C and add the constant D to the result.
 
It is important to note that the LOG function returns a fixed point number in S4.19 format instead of the standard S.23 format, which in turn means that the most negative Base2 LOG value is –16.  
 
The LOG instruction can handle absolute linear accumulator values from 0.99999988 to 0.00001526 which translates to a dynamic range of apx. 96dB.
 
D an offset to be added to the logarithmic value in the range of –16 to + 15.999998.
{| class="wikitable"
{| class="wikitable"
|+Parameters
|+Parameters
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!Entry formats, range
!Entry formats, range
|-
|-
|M
|C
|24 Bit
|16 Bit
|Binary
|Real (S1.14)
Hex ($000000 - $FFFFFF)
Hex ($0000 ­ $FFFF)
Symbolic
|-
|D
|11 Bit
|Real(S4.6)
Symbolic
Symbolic
|}
|}


======Syntax======
======Syntax======
XOR M
LOG C, D


======Coding Example======
======Coding Example======
<syntaxhighlight line="1">
<syntaxhighlight line="1">
XMASK EQU  $AAAAAA                          ;
log 1.0,0
                                            ;
;-------------------------------------------
sof 0,0                                   ; Clear all bits within ACC
xor  $0                                    ; Set all ACC bits
xor  %01010101_01010101_01010101            ; Invert all even numbered bits
xor  XMASK                                  ; Invert all odd numbered bits
</syntaxhighlight>
</syntaxhighlight>

Revision as of 20:54, 6 January 2023

LOG

Mnemonic Operation Instruction coding
LOG C * LOG(|ACC|) + D CCCCCCCCCCCCCCCCDDDDDDDDDDD01011
Description

LOG will multiply the Base2 LOG of the current absolute value in ACC with C and add the constant D to the result.

It is important to note that the LOG function returns a fixed point number in S4.19 format instead of the standard S.23 format, which in turn means that the most negative Base2 LOG value is –16.

The LOG instruction can handle absolute linear accumulator values from 0.99999988 to 0.00001526 which translates to a dynamic range of apx. 96dB.

D an offset to be added to the logarithmic value in the range of –16 to + 15.999998.

Parameters
Name Width Entry formats, range
C 16 Bit Real (S1.14)

Hex ($0000 ­ $FFFF) Symbolic

D 11 Bit Real(S4.6)

Symbolic

Syntax

LOG C, D

Coding Example
log  1.0,0
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