74F579数据手册集成电路（IC）的计数器除法器规格书PDF

描述 Description

DESCRIPTION
The 74F579 is a fully synchronous 8-stage Up/Down Counter with multiplexed 3-State I/O ports for bus-oriented applications. It features a preset capability for programmable operation, carry look-ahead for easy cascading and a U/D input to control the direction of counting. All state changes, except for the case of asynchronous reset, are initiated by the rising edge of the clock. TC output is not recommended for use as a clock or asynchronous reset due to the possibility of decoding spikes.FEATURES
• Fully synchronous operation
• Multiplexed 3-State I/O ports for bus oriented applications
• Built in cascading carry capability
• U/D pin to control direction of counting
• Separate pins for Master reset and Synchronous operation
• Center power pins to reduce effects of package inductance
• Count frequency 115MHz Typ
• Supply current 100mA Typ
• See 74F269 for 24-pin separate I/O port version
• See 74F779 for 16-pin version

特性 Features

• Fully synchronous operation
• Multiplexed 3-State I/O ports for bus oriented applications
• Built in cascading carry capability
• U/D pin to control direction of counting
• Separate pins for Master reset and Synchronous operation
• Center power pins to reduce effects of package inductance
• Count frequency 115MHz Typ
• Supply current 100mA Typ
• See 74F269 for 24-pin separate I/O port version
• See 74F779 for 16-pin version