# SN54LS181

## 算術邏輯單元/函數產生器

### 產品詳細資料

Technology family LS Bits (#) 4 Rating Military Operating temperature range (°C) -55 to 125
Technology family LS Bits (#) 4 Rating Military Operating temperature range (°C) -55 to 125
CDIP (J) 24 425.45 mm² 31.75 x 13.4
• Full Look-Ahead for High-Speed Operations on Long Words
• Input Clamping Diodes Minimize Transmission-Line Effects
• Darlington Outputs Reduce Turn-Off Time
• Arithmetic Operating Modes:
• Subtraction
• Shift Operand A One Position
• Magnitude Comparison
• Plus Twelve Other Arithmetic Operations
• Logic Function Modes:
• Exclusive-OR
• Comparator
• AND, NAND, OR, NOR
• Plus Ten Other Logic Operations

• Full Look-Ahead for High-Speed Operations on Long Words
• Input Clamping Diodes Minimize Transmission-Line Effects
• Darlington Outputs Reduce Turn-Off Time
• Arithmetic Operating Modes:
• Subtraction
• Shift Operand A One Position
• Magnitude Comparison
• Plus Twelve Other Arithmetic Operations
• Logic Function Modes:
• Exclusive-OR
• Comparator
• AND, NAND, OR, NOR
• Plus Ten Other Logic Operations

If high speed is not of importance, a ripple-carry input (Cn) and a ripple-carry output (Cn+4) are available. However, the ripple-carry delay has also been minimized so that arithmetic manipulations for small word lengths can be performed without external circuitry.

The 'LS181 and 'S181 will accommodate active-high data if the pin designations are interpreted as follows:

Subtraction is accomplished by 1's complement addition where the 1's complement of the subtrahend is generated internally.The resultant output is A – B – 1, which requires an end-around or forced carry to provide A – B.

The 'LS181 or 'S181 can also be utilized as a comparator. The A = B output is internally decoded from the function outputs (F0, F1, F2, F3) so that when two words of equal magnitude are applied at the A and B inputs, it will assume a high level to indicate equality (A = B). The ALU must be in the subtract mode with Cn = H when performing this comparison. The A = B output is open-collector so that it can be wire-AND connected to give a comparison for more than four bits. The carry output (Cn+4) can also be used to supply relative magnitude information. Again, the ALU must be placed in the subtract mode by placing the function select inputs S3, S2, S1, S0 at L, H, H, L, respectively.

These circuits have been designed to not only incorporate all of the designer's requirements for arithmetic operations, but also to provide 16 possible functions of two Boolean variables without the use of external circuitry. These logic functions are selected by use of the four function-select inputs (S0, S1, S2, S3) with the mode-control input (M) at a high level to disable the internal carry. The 16 logic functions are detailed in Tables 1 and 2 and include exclusive-OR, NAND, AND, NOR, and OR functions.

Series 54, 54LS, and 54S devices are characterized for operation over the full military temperature range of -55°C to 125°C; Series 74LS and 74S devices are characterized for operation from 0°C to 70°C.

If high speed is not of importance, a ripple-carry input (Cn) and a ripple-carry output (Cn+4) are available. However, the ripple-carry delay has also been minimized so that arithmetic manipulations for small word lengths can be performed without external circuitry.

The 'LS181 and 'S181 will accommodate active-high data if the pin designations are interpreted as follows:

Subtraction is accomplished by 1's complement addition where the 1's complement of the subtrahend is generated internally.The resultant output is A – B – 1, which requires an end-around or forced carry to provide A – B.

The 'LS181 or 'S181 can also be utilized as a comparator. The A = B output is internally decoded from the function outputs (F0, F1, F2, F3) so that when two words of equal magnitude are applied at the A and B inputs, it will assume a high level to indicate equality (A = B). The ALU must be in the subtract mode with Cn = H when performing this comparison. The A = B output is open-collector so that it can be wire-AND connected to give a comparison for more than four bits. The carry output (Cn+4) can also be used to supply relative magnitude information. Again, the ALU must be placed in the subtract mode by placing the function select inputs S3, S2, S1, S0 at L, H, H, L, respectively.

These circuits have been designed to not only incorporate all of the designer's requirements for arithmetic operations, but also to provide 16 possible functions of two Boolean variables without the use of external circuitry. These logic functions are selected by use of the four function-select inputs (S0, S1, S2, S3) with the mode-control input (M) at a high level to disable the internal carry. The 16 logic functions are detailed in Tables 1 and 2 and include exclusive-OR, NAND, AND, NOR, and OR functions.

Series 54, 54LS, and 54S devices are characterized for operation over the full military temperature range of -55°C to 125°C; Series 74LS and 74S devices are characterized for operation from 0°C to 70°C.

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### 技術文件

star =TI 所選的此產品重要文件

* Data sheet Arithmetic Logic Units/Function Generators datasheet 1988年 3月 1日
Selection guide Logic Guide (Rev. AB) 2017年 6月 12日
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 2015年 12月 2日
User guide LOGIC Pocket Data Book (Rev. B) 2007年 1月 16日
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 2004年 7月 8日
Application note TI IBIS File Creation, Validation, and Distribution Processes 2002年 8月 29日
Application note Designing With Logic (Rev. C) 1997年 6月 1日
Application note Designing with the SN54/74LS123 (Rev. A) 1997年 3月 1日
Application note Input and Output Characteristics of Digital Integrated Circuits 1996年 10月 1日
Application note Live Insertion 1996年 10月 1日

### 設計與開發

CDIP (J) 24 Ultra Librarian

• RoHS
• REACH
• 產品標記
• 鉛塗層/球物料
• MSL 等級/回焊峰值
• MTBF/FIT 估算值
• 材料內容
• 認證摘要
• 進行中持續性的可靠性監測

• 晶圓廠位置
• 組裝地點