TL16C554A

具有 16 字节 FIFO 的四路 UART

The is an enhanced quadruple version of the TL16C550C asynchronous-communications element ACE. Each channel performs serial-to-parallel conversion on data characters received from peripheral devices or modems and parallel-to-serial conversion on data characters transmitted by the CPU. The complete status of each channel of the quadruple ACE can be read by the CPU at any time during operation. The information obtained includes the type and condition of the operation performed and any error conditions encountered.

The TL16C554A quadruple ACE can be placed in an alternate FIFO mode, which activates the internal FIFOs to allow 16 bytes plus three bits of error data per byte in the receiver FIFO to be stored in both receive and transmit modes. In the FIFO mode of operation, there is a selectable autoflow control feature that can significantly reduce software overhead and increase system efficiency by automatically controlling serial-data flow using RTS output and CTS input signals. All logic is on the chip to minimize system overhead and maximize system efficiency. Two terminal functions allow signaling of direct-memory access DMA transfers. Each ACE includes a programmable baud-rate generator that can divide the timing reference clock input by a divisor between 1 and 216 – 1.

The TL16C554A is available in a 68-pin plastic-leaded chip-carrier PLCC FN package, 64-pin plastic quad flatpack PQFP PM package and in an 80-pin TQFP PN package.

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Integrated Asynchronous-Communications Element

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Consists of Four Improved TL16C550C ACEs Plus Steering Logic

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In FIFO Mode, Each ACE Transmitter and Receiver Is Buffered

With 16-Byte FIFO to Reduce the Number of Interrupts to CPU

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In TL16C450 Mode, Hold and Shift Registers Eliminate Need for Precise

Synchronization Between the CPU and Serial Data

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Up to 16-MHz Clock Rate for up to 1-Mbaud Operation with VCC = 3.3 V and 5 V

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Programmable Baud-Rate Generators Which Allow Division of Any Input Reference Clock

by 1 to 216 – 1 and Generate an Internal 16 × Clock

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Adds or Deletes Standard Asynchronous Communication Bits Start, Stop, and

Parity to or From the Serial-Data Stream

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Independently Controlled Transmit, Receive, Line Status, and Data Set Interrupts

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5-V and 3.3-V Operation

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Fully Programmable Serial Interface Characteristics:

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5-, 6-, 7-, or 8-Bit Characters

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Even-, Odd-, or No-Parity Bit

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1-, 1 1/2-, or 2-Stop Bit Generation

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Baud Generation DC to 1-Mbit Per Second

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False Start Bit Detection

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Complete Status Reporting Capabilities

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Line Break Generation and Detection

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Internal Diagnostic Capabilities:

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Loopback Controls for Communications Link Fault Isolation

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Break, Parity, Overrun, Framing Error Simulation

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Fully Prioritized Interrupt System Controls

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Modem Control Functions CTS, RTS, DSR, DTR, RI, and DCD

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3-State Outputs Provide TTL Drive Capabilities for Bidirectional Data Bus

and Control Bus

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Programmable Auto-RTS and Auto-CTS

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CTS Controls Transmitter in Auto-CTS Mode,

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RCV FIFO Contents and Threshold Control RTS in Auto-RTS Mode,