- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄371370 > 21928 Low-Frequency, Spread-Spectrum EconOscillator PDF資料下載
參數(shù)資料
| 型號(hào)： | 21928 |
| 英文描述： | Low-Frequency, Spread-Spectrum EconOscillator |
| 中文描述： | 的AMD - K6 - 2E處理器數(shù)據(jù)手冊(cè)3DNow！？技術(shù)手冊(cè) |
| 文件頁數(shù)： | 71/72頁 |
| 文件大小： | 845K |
| 代理商： | 21928 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁當(dāng)前第71頁第72頁
Chapter 3
Division and Square Root
61
21928G/0—March 2000
3DNow! Technology Manual
Square Root
The 3DNow! instructions can also be used to compute a
reciprocal square root or square root with high performance.
The general Newton-Raphson reciprocal square root recurrence
is as follows:
Z
i +1
←
1
/2 Z
i
(3 – b Z
i
2
)
To reduce the number of iterations, the initial approximation is
read from a table. The 3DNow! reciprocal square root
approximation is accurate to at least 15 bits. Accordingly, to
obtain a single-precision 24-bit reciprocal square root of an
input operand b, one Newton-Raphson iteration is required
using the following 3DNow! instructions:
1. X
0
= PFRSQRT(b)
2. X
1
= PFMUL(X
0
, X
0
)
3. X
2
= PFRSQIT1(b, X
1
)
4. X
3
= PFRCPIT2(X
2
, X
0
)
5. X
4
= PFMUL(b, X
3
)
The 24-bit final reciprocal square root value is X
3
. In the AMD
implementation, the estimate contains the correct
round-to-nearest value for approximately 87% of all arguments.
The remaining arguments differ from the correct
round-to-nearest value by 1 ulp. The square root (X
4
) is formed
in the last step by multiplying by the input operand b.
Square Root Examples
These examples illustrate the use of 3DNow! technology to
perform square roots.
(15-Bit Precision)
MOVD
PFRSQRT
PUNPCKLDQ MM0, MM0
PFMUL
MM0, [mem]
MM1, MM0
;
; 1/(sqrt a) | 1/(sqrt a) (approx.)
;
a | a
;
(sqrt a) | (sqrt a)
0 | a
(MMX instr.)
MM0, MM1
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 2192VE | 3.3V In-System Programmable SuperFAST⑩ High Density PLD |
| 21934 | CAPACITIVE SENSOR |
| 21A | Low-Frequency Dual EconOscillator |
| 21B | Low-Frequency Dual EconOscillator |
| 21C | Low-Frequency Dual EconOscillator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 219-2-8235-1 | 制造商:Airpax 功能描述:CIRCUIT PROTECTOR HYD MAGNETIC 制造商:Airpax 功能描述:CIRCUIT BREAKER MAG-HYDR LEVER 制造商:Sensata Technologies 功能描述:219-2-8235-1 /Pole # 2 /Prod Family: 0209 |
| 219-2-8696-1 | 制造商:Airpax 功能描述:CIRCUIT BREAKER MAG-HYDR LEVER 制造商:Sensata Technologies 功能描述:219-2-8696-1 /Pole # 2 /Prod Family: 0209 |
| 21-9290 | 制造商:Tenma 功能描述:Soldering Iron Pencil 25W 制造商:TENMA 功能描述:PENCIL SOLDERING IRON 25 WATT |
| 219-2-9344-1 | 制造商:Airpax 功能描述:CIRCUIT PROTECTOR HYD MAGNETIC 制造商:Sensata Technologies 功能描述:219-2-9344-1 /Pole # 2 /Prod Family: 0209 |
| 21-9295 | 制造商:Tenma 功能描述:Soldering Iron Pencil 45W 制造商:TENMA 功能描述:PENCIL SOLDERING IRON 40 WATT |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。