W83977G Winbond Electronics Corp America, W83977G Datasheet - Page 125

• Manufacturer Part Number: W83977G
• Description: W83877TF plus KBC, CIR, RTC, Pb-free
• Manufacturer: Winbond Electronics Corp America

W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
12. PLUG AND PLAY CONFIGURATION
The W83977F/G, W83977AF/AG provides many configuration registers for setting up different types
of configurations. There are two approaches to entering the configuration state and accessing these
configuration registers, Comply PnP and Compatible PnP. The Comply PnP protocol is based on the
Plug and Play ISA Specification. The Compatible PnP protocol is similar to previous Winbond I/O's
protocol.
The Power-On-Setting upon the Pin 51 ( DTRB ) decides the method of entering the
configuration mode. In W83977F/G, W83977AF/AG, there are nine Logical Devices (from Logical
Device 0 to Logical Device 8) which correspond to nine individual functions: FDC, PRT, UART1,
UART2, RTC, KBC, IR, GPIO1, GPIO2 in listed order. Each Logical Device has its own configuration
registers (above CR30). Host can access those registers only after entering configuration mode.
12.1 Comply PnP
The protocol of Comply PnP is 100% compatible with the Plug and Play ISA Specification. W83977F/
G, W83977AF provide built-in Plug and Play state machine to control the configuration flow. The state
machine supports four states: Wait for Key state, Sleep state, Isolation state, and Configure State.
According to Plug and Play ISA Specification, users can transit the four states by accessing the
configuration registers, CR00 - CR07.
12.1.1
Wait for Key State
All cards enter this state after power-up reset or in response to the Reset and Wait for Key
commands. No command is active in this state until the initiation key is detected on the ISA bus. The
initiation key is a sequence of 32 hexadecimal number which will be shifted into LFSR (linear
feedback shift register) built in W83977F/G, W83977AF/AG. The Wait for Key state is the default
state for Plug and Play cards during normal system operation. After configuration and activation,
software should return all cards to this state.
Publication Release Date: May 2006
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Revision 0.60