SC26C92

General description

The SC26C92 is a pin and function replacement for the SCC2692 and SCN2681 with added features and deeper FIFOs. Its configuration on power up is that of the 2692. Its differences from the 2692 are: 8 character receiver, 8 character transmit FIFOs, watch dog timer for each receiver, mode register 0 is added, extended baud rate and overall faster speeds, programmable receiver and transmitter interrupts. (The SCC2692 is not being discontinued.)

The Philips Semiconductors SC26C92 Dual Universal Asynchronous Receiver/Transmitter (DUART) is a single-chip CMOS-LSI communications device that provides two full-duplex asynchronous receiver/transmitter channels in a single package. It interfaces directly with microprocessors and may be used in a polled or interrupt driven system and provides modem and DMA interface.

The operating mode and data format of each channel can be programmed independently. Additionally, each receiver and transmitter can select its operating speed as one of 27 fixed baud rates, a 16X clock derived from a programmable counter/timer, or an external 1X or 16X clock. The baud rate generator and counter/timer can operate directly from a crystal or from external clock inputs. The ability to independently program the operating speed of the receiver and transmitter make the DUART particularly attractive for dual-speed channel applications such as clustered terminal systems.

Each receiver and transmitter is buffered by eight character FIFOs to minimize the potential of receiver overrun, transmitter underrun and to reduce interrupt overhead in interrupt driven systems. In addition, a flow control capability is provided via RTS/CTS signaling to disable a remote transmitter when the receiver buffer is full.

Also provided on the SC26C92 are a multipurpose 7-bit input port and a multipurpose 8-bit output port. These can be used as general purpose I/O ports or can be assigned specific functions (such as clock inputs or status/interrupt outputs) under program control.

The SC26C92 is available in three package versions: 40-pin 0.6" wide DIP, a 44-pin PLCC and 44-pin plastic quad flat pack (PQFP).

Features

• Dual full-duplex independent asynchronous receiver/transmitters
• 8 character FIFOs for each receiver and transmitter
• Programmable data format
  • 5 to 8 data bits plus parity
  • Odd, even, no parity or force parity
  • 1, 1.5 or 2 stop bits programmable in 1/16-bit increments
• 16-bit programmable Counter/Timer
• Programmable baud rate for each receiver and transmitter selectable from:
  • 27 fixed rates: 50 to 230.4k baud
  • Other baud rates to 230.4k baud at 16X
  • Programmable user-defined rates derived from a programmable counter/timer
  • External 1X or 16X clock
• Parity, framing, and overrun error detection
• False start bit detection
• Line break detection and generation
• Programmable channel mode
  • Normal (full-duplex)
  • Automatic echo
  • Local loopback
  • Remote loopback
  • Multidrop mode (also called ?wake-up? or ?9-bit?)
• Multi-function 7-bit input port
  • Can serve as clock, modem, or control inputs
  • Change of state detection on four inputs
  • Inputs have typically >100k pull-up resistors
• Multi-function 8-bit output port
  • Individual bit set/reset capability
  • Outputs can be programmed to be status/interrupt signals
  • FIFO states for DMA and modem interface
• Versatile interrupt system
  • Single interrupt output with eight maskable interrupting conditions
  • Output port can be configured to provide a total of up to six separate wire-ORable interrupt outputs
  • Each FIFO can be programmed for four different interrupt levels
  • Watch dog timer for each receiver
• Maximum data transfer rates: 1X - 1Mb/sec, 16X - 1Mb/sec
• Automatic wake-up mode for multidrop applications
• Start-end break interrupt/status
• Detects break which originates in the middle of a character
• On-chip crystal oscillator
• Power down mode
• Receiver timeout mode
• Single +5V power supply
• Powers up to emulate SCC2692

Products/packages

The variants in the table below are discontinued. See the table Discontinued information for more information.

Quality/reliability/chemical content

The variants in the table below are discontinued. See the table Discontinued information for more information.

Quality and reliability disclaimer

Pricing/ordering/availability

Discontinued information

Applications

Related applications
LCD TV - MMS functionality
Set-top box - MMS functionality

Design support

Application Notes

AN10320; Addressing migrations of SCN devices to more advanced technologies (2004-06-29)

AN10353; Application of UART in GPS navigation system (2005-03-01)

AN10251; Automatic '485' turn-around (2003-10-27)

AN10307; UART to Bluetooth interfacing (2004-08-11)

Support Documents

web; IBIS and HSPICE Model ()

Parametrics/similar products

Similar products
SC26C92 links to the similar products page containing an overview of products that are similar in function or related to the type number(s) as listed on this page. The similar products page includes products from the same catalog tree(s), relevant selection guides and products from the same functional category.

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer