OPTi 82C493/392/206 (486SXWB PC/AT)
Chipset parts: OPTi 82C392 (DBC) OPTi 82C493 (any brand) 82C206

Documented parts


82C392 Data Buffer Controller (DBC)

Features:

  • Data Bus Conversion
  • Parity Generation/Detection
  • AT-BUS direction control
  • Reset logic
  • Clock source for 206 and 8042
  • Chip select for Keyboard Controller and ATC
  • Speaker Control
  • Port B, 70H and NMI logic
  • Numerical Processor Interface
  • Keyboard reset and Gate A20 emulation logic

The 82C206 Integrated Peripheral Controller (IPC) is a single-chip integration of all the main peripheral parts attached to the X bus of PC/AT architecture. The 82C206 replaces the following peripheral logic on motherboards:

  • two 8237 DMA controllers
  • two 8259A interrupt controllers
  • one 8254 timer/counter
  • one 146818A-compatible real-time clock
  • one 74LS612 memory mapper

Provides:

  • Seven DMA channels
  • 13 interrupt request channels
  • two timer/counter channels

Four DMA transfer modes supported:

  • Single
  • Block
  • Demand
  • Cascade

Special Commands provided for ease of programming:

  • Clear byte pointer flip-flop
  • Set byte pointer flip-flop
  • Master clear
  • Clear request mask register
  • Clear mode register counter

Other features:

  • Contains 114 bytes of CMOS RAM
  • 8MHz DMA clock with programmable internal divider for 4MHz operation
  • 16MB DMA address space
  • Programmable wait states for DMA cycles
  • Reduced recovery time (120ns) between I/O operations for the 8237, 8259A and 8254
  • 84-pin PLCC (plastic leadless chip carrier) or 100-pin QFP (quad flat pack)
Drivers: not available
Documentation: 2 files

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