w89c926 Winbond Electronics Corp America, w89c926 Datasheet - Page 16

• Manufacturer Part Number: w89c926
• Description: Pcmcia Ethernet Network Twisted Pair Interface Controller
• Manufacturer: Winbond Electronics Corp America

CFB (Configuration Register B)
Access Address: AMBase + 00FF2H
Access Type: Attribute Memory Read/Write
BIT
1-5
BIT
0-1
0
6
7
SYMBOL
SYMBOL
PHY01
M/-IO
F/ EE
LED
-
Share Memory/IO Mode Select
The PENTIC+ will operate in shared memory mode if this bit is high;
otherwise, it will be in I/O mode.
Reserved, must be 0s.
Flash or EEPROM Select.
This bit directly reflects the sampled value on pin EECS/FCS during a
H/W reset. This bit will be high or low if EECS/FCS is pulled high or low.
This bit is read-only.
LED Disable.
Setting this bit high disables the LED indicators in order to save power.
Physical Media Select
These two bits determine to which type of medium the PENTIC+ is
attached. The THIN pin will output low in 10BASE5 mode and high in
10BASE2 mode, according to PHY0,1. This can be used to control the
DC-DC converter for electrical isolation.
The PENTIC+ also provides a UTP/BNC auto media-switching function.
The physical interface will jump from UTP to BNC when the PENTIC+ is
configured at UTP, the link checking is enabled, and the UTP path is
broken. It will jump back immediately if the UTP path has been
reconnected. When the physical interface is not configured at TPI or the
link checking is disabled, the auto media-switching function will be
disabled.
PHY1
0
0
1
1
PHY0
1
0
0
1
Attached Medium Type
TPI (10BASE-T Compatible Squelch Level)
Thin Ethernet (10BASE2)
Thick Ethernet (10BASE5)
TPI (Reduced Squelch Level)
- 16 -
DESCRIPTION
DESCRIPTION
W89C926 PENTIC+