GENERAL DESCRIPTION
This data sheet covers two products: W83977F, and W83977AF whose pin assignment, and most of the functions are the same. W83977AF is an advanced version of W83977F featuring the FIR function.

FEATURES
General
• Plug & Play 1.0A Compliant
• Support 13 IRQs, 4 DMA channels, full 16-bit addresses decoding
• Capable of ISA Bus IRQ Sharing
• Compliant with Microsoft PC97 Hardware Design Guide
• Support DPM (Device Power Management), ACPI
• Programmable configuration settings
• 24 or 14.318 Mhz clock input

FDC
• Compatible with IBM PC AT disk drive systems
• Variable write pre-compensation with track selectable capability
• Support vertical recording format
• DMA enable logic
• 16-byte data FIFOs
• Support floppy disk drives and tape drives
• Detects all overrun and underrun conditions
• Built-in address mark detection circuit to simplify the read electronics
• FDD anti-virus functions with software write protect and FDD write enable signal (write data signal was forced to be inactive)
• Support up to four 3.5-inch or 5.25-inch floppy disk drives
• Completely compatible with industry standard 82077
• 360K/720K/1.2M/1.44M/2.88M format; 250K, 300K, 500K, 1M, 2M bps data transfer rate
• Support 3-mode FDD, and its Win95 driver

UART
• Two high-speed 16550 compatible UARTs with 16-byte send/receive FIFOs
• 3rd UART with 32-byte send/receive FIFO is supported for IR function [W83977AF only]
• MIDI compatible
• Fully programmable serial-interface characteristics:
   --- 5, 6, 7 or 8-bit characters
   --- Even, odd or no parity bit generation/detection
   --- 1, 1.5 or 2 stop bits generation
• Internal diagnostic capabilities:
   --- Loop-back controls for communications link fault isolation
   --- Break, parity, overrun, framing error simulation
• Programmable baud generator allows division of 1.8461 Mhz and 24 Mhz by 1 to (216-1)
• Maximum baud rate up to 921k bps for 14.769 Mhz and 1.5M bps for 24 Mhz

Infrared
• Support IrDA version 1.0 SIR protocol with maximum baud rate up to 115.2K bps
• Support SHARP ASK-IR protocol with maximum baud rate up to 57,600 bps
• Support IrDA version 1.1 MIR (1.152M bps) and FIR (4M bps) protocol [W83977AF only]
   --- Single DMA channel for transmitter or receiver
   --- 3rd UART with 32-byte FIFO is supported in both TX/RX transmission [W83977AF only]
   --- 8-byte status FIFO is supported to store received frame status (such as overrun CRC error, etc.)
• Support auto-config SIR and FIR [W83977AF only]

Parallel Port
• Compatible with IBM parallel port
• Support PS/2 compatible bi-directional parallel port
• Support Enhanced Parallel Port (EPP) - Compatible with IEEE 1284 specification
• Support Extended Capabilities Port (ECP) - Compatible with IEEE 1284 specification
• Extension FDD mode supports disk drive B; and Extension 2FDD mode supports disk drives A and B through parallel port
• Enhanced printer port back-drive current protection

Advanced Power Management (APM) Controlling
• Power turned on when RTC reaches a preset date and time
• Power turned on when a ring pulse or pulse train is detected on the PHRI, or when a high to low transition on PWAKIN1, or PWAKIN2 input signals
• Power turned on when PANSW input signal indicates a switch on event
• Power turned off when PANSW input signal indicates a switch off event
• Power turned off when a fail-safe event occurs (power-save mode detected but system is hung up)
• Power turned off when software issues a power off command

Keyboard Controller
• 8042 based with optional F/W from AMIKKEYTM-2, Phoenix MultiKey/42TM or customer code with 2K bytes of programmable ROM, and 256 bytes of RAM
• Asynchronous Access to Two Data Registers and One status Register
• Software compatibility with the 8042 and PC87911 microcontrollers
• Support PS/2 mouse
• Support port 92
• Support both interrupt and polling modes
• Fast Gate A20 and Hardware Keyboard Reset
• 8 Bit Timer/ Counter; support binary and BCD arithmetic
• 6, 8, 12, or 16 Mhz operating frequency (16 Mhz available only if input clock rate = 14.318 Mhz)