
8/01/00
Am79C976
185
P R E L I M I N A R Y
or a direct register write has been
performed on this register.
Read/Write accessible. These
bits are cleared by H_RESET but
are unaffected by S_RESET, or
STOP.
0+$(
Note:
Bits 15-0 in this register are programmable
through the EEPROM.
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
PADR[31:16]Physical
Address
Register,
PADR[31:16]. The contents of
this register are loaded from EE-
PROM after H_RESET or by an
EEPROM
read
(PREAD, BCR19, bit 14). If the
EEPROM is not present, the con-
tents of this register are unde-
fined.
command
This register can also be loaded
from the initialization block after
the INIT bit in CSR0 has been set
or a direct register write has been
performed on this register.
Read/Write accessible. These
bits are cleared by H_RESET but
are unaffected by S_RESET, or
STOP.
"0+$(
Note:
Bits 15-0 in this register are programmable
through the EEPROM.
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
PADR[47:32]Physical
Address
Register,
PADR[47:32].The contents of
this register are loaded from
EEPROM after H_RESET or by
an EEPROM read command
(PREAD, BCR19, bit 14). If the
EEPROM is not present, the con-
tents of this register are unde-
fined.
This register can also be loaded
from the initialization block after
the INIT bit in CSR0 has been set
or a direct register write has been
performed on this register.
Read/Write accessible. These
bits are cleared by H_RESET but
are unaffected by S_RESET, or
STOP.
)#
This register
’
s fields are loaded during the Am79C976
controller initialization routine with the corresponding
Initialization Block values, or when a direct register write
has been performed on this register.
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15
PROM
Promiscuous
PROM = 1, all incoming receive
frames are accepted.
Mode.
When
Read/Write accessible.
14
DRCVBC
Disable
When
Am79C976 controller from re-
ceiving broadcast messages.
Used for protocols that do not
support broadcast addressing,
except as a function of multicast.
DRCVBC is cleared by activation
of
H_RESET
(broadcast messages will be re-
ceived) and is unaffected by
STOP.
Receive
set,
Broadcast.
disables
the
or
S_RESET
Read/Write accessible.
13
DRCVPA
Disable Receive Physical Ad-
dress. When set, the physical ad-
dress detection (Station or node
ID) of the Am79C976 controller
will be disabled. Frames ad-
dressed to the node
’
s individual
physical address will not be rec-
ognized.
Read/Write accessible.
12-9
RES
Reserved locations. Written as
zeros and read as undefined.
8-7
PORTSEL[1:0]Obsolete function. Writing has
no effect. Read as undefined.
6
INTL
Obsolete function. Writing has no
effect. Read as undefined.