w89c940 Winbond Electronics Corp America, w89c940 Datasheet - Page 24

• Manufacturer Part Number: w89c940
• Description: Elanc-pci Twisted-pair Ether-lan Controller With Pci Interface
• Manufacturer: Winbond Electronics Corp America

The signature register can be read by PCI Configuration Cycle with address 40H. The consecutive read will get
a data pattern 88H, 00H, 88H, 00H,.... if byte enable (C_BEB#) is asserted. A write operation will have no effect
on the content of this signature register.
W89C940 includes some control circuit and status register bits to generate interrupt signal early during
receiving packets. Besides traditional interrupt generated at incoming packet end, W89C940 can generate
interrupt when received packet bytes reach
EIR_STATU
EIR_MASK
Registers
EIR_EN
S
PHY1
0
0
0
0
0
1
1
1
1
1
IO Address
Base+0bh
Base+0bh
Base+0bh
Page 0
Page 0
Page 0
[0]
[1]
[7]
PHY0
0
0
0
1
1
0
0
1
1
1
Early Interrupt Enable Register: Read/Write
Asserted high to enable Early Interrupt Function. Deasserted to
disable Early Interrupt Function. To program Receive Control
Register (RCR) to monitor mode or Data Configuration Register
(DCR) to Loopback mode will also disable Early Interrupt
Function. Initial value after Power-on Reset is 0. Read once
write.
Early Interrupt Mask Register: Read/Write
Asserted high to initiate an interrupt on INTA# of PCI local bus
when an Early Interrupt Event occured. Deasserted this register
will mask an interrupt generated. Deasserted this register does
not disable Early Interrupt Status Register. Initial value after
Power-on Reset is 0.Read once write.
Early Interrupt Status Register: Read/Write
Asserted high when the byte count of incoming frame reaches
Early Interrupt Threshold with correct destination address (DS), in
the enable mode of Early Interrupt Function. Write 1 to clear
EIR_STATUS. Initial value after Power-on Reset is 0. Read
once write.
Descriptions
LNKEN
1
0
0
1
0
1
0
1
0
0
Early Interrupt Threshold
GDLNK
0 or 1
0 or 1
1
1
0
1
1
1
1
0
24
disabled, keep at UTP
enabled, keep at UTP
enabled, UTP switch to BNC or AUI
disabled, keep at AUI
disabled, keep at AUI
disabled, keep at AUI
disabled, keep at AUI
disabled, keep at UTP
enabled,
enabled,
Auto Switching Function
keep at UTP
UTP switch to BNC or AUI
and early interrupt function is enabled.
W89C940