am79c961a Advanced Micro Devices, am79c961a Datasheet - Page 53

• Manufacturer Part Number: am79c961a
• Description: Pcnet?-isa Ii Jumperless, Full Duplex Single-chip Ethernet Controller For Isa
• Manufacturer: Advanced Micro Devices

Set RD_DATA Port
Serial Isolation
Config Control
Wake[CSN]
Resource Data
Status
Card Select Number
Logical Device Number
Name
Port Value
Address
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
Plug and Play Standard Registers
Definition
Writing to this location modifies the address of the port used for reading from the
Plug and Play ISA cards. Bits[7:0] become I/O read port address bits [9:2].
Reads from this register are ignored. I/O Address bits 11:10 should = 00, and 1:0 = 11.
A read to this register causes a Plug and Play card in the Isolation state to
compare one bit of the board’s ID. This process is fully described above. This
register is read only.
Bit[0] - Reset all logical devices and restore configuration registers to their
power-up values.
Bit[1] - Return to the Wait for Key state
Bit[2] - Reset CSN to 0
A write to bit[0] of this register performs a reset function on all logical devices.
This resets the contents of configuration registers to their default state. All card’s
logical devices enter their default state and the CSN is preserved.
A write to bit[1] of this register causes all cards to enter the Wait for Key state but
all CSNs are preserved and logical devices are not affected.
A write to bit[2] of this register causes all cards to reset their CSN to zero.
This register is write-only. The values are not sticky, that is, hardware will
automatically clear them and there is no need for software to clear the bits.
A write to this port will cause all cards that have a CSN that matches the write
data[7:0] to go from the Sleep state to either the Isolation state if the write data
for this command is zero or the Config state if the write data is not zero. This
register is write-only. Writing to this register resets the EEPROM pointer to the
beginning of the Plug and Play Data Structure.
A read from this address reads the next byte of resource information. The Status
register must be polled until bit[0] is set before this register may be read. This
register is read-only.
Bit[0] when set indicates it is okay to read the next data byte from the Resource
Data register. This register is read-only.
A write to this port sets a card’s CSN. The CSN is a value uniquely assigned to
each ISA card after the serial identification process so that each card may be
individually selected during a Wake [CSN] command. This register is read/write.
Selects the current logical device. This register is read only. The PCnet-ISA II
controller has only 1 logical device, and this register contains a value of 0x00
Am79C961A
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