Theory of Operation 4-21
• Parallel Port
• Enhanced Parallel Port(EPP) compa t i ble
• Extended Capabilities Port(ECP) compatible, including level 2 support
• Bidirectional under either software or hardware control
• Compatible with ISA, and EISA, architectures
• Ability to multiplex FDC signals on parallel port pins allows use of an external Floppy Disk
Drive(FDD)
• Includes protection circuit to prevent damage to the parallel port when a connected printer is
powered up or is operated at a higher voltage
• The UARTs:
• Software compatible with the PC16550A and PC16450
• MIDI baud rate support
• Infrared support on UART2(IrDA and Sharp-compliant)
• The Address Decoder
• 6 bit or 10 bit decoding
• External Chip Select capability when 10 bit decoding
• Full relocation capability(No limitation)
• Enhanced Power Management
• Special configura tion registers for p ower-down
• Enhanced programmable power-down FDC command
• Auto power-down and wake-up modes
• 2 special pins for power management
• Typical current consumption during power-down is less than 10 uA
• Reduced pin leakage current
• Mixed Voltage support
• Supports standard 5V operation
• Supports 3.3V operation
• Supports mixed internal 3.3V operation with 3.3V/5V external configuration
• The General Purpose Pins:
• 2 pins The Bidirectional Parallel Port:, for 2 separate programmable chip select decoders, can
be programmed for game port control