w89c940 Winbond Electronics Corp America, w89c940 Datasheet - Page 15

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

MCR
A mode configuration register(MCR) is used to program the operation mode of the ELANC-PCI. The address is
page 0, 0AH. MCR can be updated by software. Reading this register is the same as reading a register in the
SLCT core coprocessor. Writing to these registers is done by first reading the register to be written to and then
using a slave write operation to update the configurations.
The content of MCR is as following table:
0
1
2
3
4
5
6
7
GDLNK
LNKEN
PHY0
PHY1
SHLS
BPS0
BPS1
BPS2
Physical Layer Interface:
These two bits select the type of physical interface which the ELANC-PCI
attached on. Both the thin Ehternet and thick Ethernet type use the AUI of
ELANC-PCI as the input/output interface. The other two UTP types,then, use
the TPI of ELANC-PCI as the input/output interface. The output and input pins
of AUI or TPI are idle, when the corresponding type is not selected.
PHY1 PHY0
Good Link Status:
A read operation on this bit will get the link test status. A "1" indicate that it is
link good and a "0" is link fail.
The GDLNK do not imply any information if the PHY0 and PHY1 is
programmed as Thin or Thick Ethernet.
Link Test Pulse enable:
The network media auto switching function, link integrity test function and the
link test pulse generation function will be enabled when LNKEN = "0".
Otherwise, all of these functions will be disabled when LNKEN = "1".
SRAM High/Low Speed Select:
High speed SRAM with 20nsec access time is selected if SHLS =1. Low
speed SRAM with 70nsec access time is selected if SHLS =0.
BOOT PROM Size:
The size of the BOOT PROM is selected by BPS0, BPS1, and BPS2.
BPS2 BPS1 BPS0
0
0
1
1
0
0
0
1
1
1
1
0
1
0
1
0
1
1
0
0
1
1
X
0
1
0
1
0
1
UTP (with 10BASE-T compatible receive squelch level)
Thin Ethernet
Thick Ethernet (AUI port)
UTP (with reduced receive squelch level)
Physical Interface Type
No boot PROM
128K
256K
16K
32K
64K
8K
SIZE
15
W89C940