154
Am79C965A
and listens for Link Pulses. LNKST
indicates Link Status and goes
active if the 10BASE-T port comes
of out of
“
link fail
”
state. This LNKST
pin can be used by external circuitry
to re-enable the PCnet-32 controller
and/or other devices.
When AWAKE =
“
0
”
, the Auto-Wake
circuitry is disabled. This bit only has
meaning when the 10BASE-T
network interface is selected.
This bit is reset to ZERO by
H_RESET and is unaffected by
S_RESET or STOP.
1
ASEL
Auto
PCnet-32 controller will auto-
matically select the operating media
interface port, unless the user has
selected GPSI mode through
appropriate programming of the
PORTSEL bits of the Mode Register
(CSR15). If GPSI mode has not
been selected and ASEL has been
set to a ONE, then when the
10BASE-T transceiver is in the link
pass state (due to receiving valid
frame data and/or Link Test pulses
or the DLNKTST bit is set), the
10BASE-T port will be used. If GPSI
mode has not been selected and
ASEL has been set to a ONE, then
when the 10BASE-T port is port will
be used. Switching between the
ports will not occur during
transmission, to avoid any type of
fragment generation.
Select.
When
set,
the
When ASEL is set to ONE, Link Beat
Pulses will be transmitted on the
10BASE-T port, regardless of the
state of Link Status. When ASEL is
reset to ZERO, Link Beat Pulses will
only be transmitted on the
10BASE-T port when the PORTSEL
bits of the Mode Register (CSR15)
have selected 10BASE-T as the
active port.
When ASEL is set to a ZERO, then
the selected network port will be
determined by the settings of the
PORTSEL bits of CSR15.
The ASEL bit is reset to ONE by
H_RESET and is unaffected by
S_RESET or STOP.
The network port configuration are
as follows:
0
RES
Reserved location. The default
value of this bit is a ZERO. Writing a
ONE to this bit has no effect on
device function. Existing drivers may
write a ONE to this bit, but new
drivers should write a ZERO to this
bit.
BCR4: Link Status LED
Bit
Name
Description
BCR4 controls the function(s) that
the LNKST pin displays. Multiple
functions can be simultaneously
enabled on this LED pin. The LED
display will indicate the logical OR of
the enabled functions. BCR4
defaults to Link Status (LNKST) with
pulse stretcher enabled (PSE = 1)
and is fully programmable.
The default setting after H_RESET
for the LNKST register is 00C0h.
The LNKST register value is
unaffected by S_RESET or STOP.
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15
LEDOUT This bit indicates the current (non-
stretched) value of the LED output
pin. A value of ONE in this bit
indicates that the OR of the enabled
signals is true.
The logical value of the LEDOUT
status signal is determined by the
settings of the individual Status
Enable bits of the LED register (Bits
6-0).
This bit is READ only by the host,
and is unaffected by H_RESET or
S_RESET or STOP.
This bit is valid only if the network
link status is PASS.
PORTSEL(1:0)
ASEL
(BCR2[1])
Link Status
(of 10BASE-T)
Network
Port
0X
1
0
AUI
0X
1
1
10BASE-T
0 0
0
X
AUI
0 1
0
X
10BASE-T
1 0
X
X
GPSI
1 1
X
X
Reserved