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140
Am79C973/Am79C975
P R E L I M I N A R Y
CSR17: Initialization Block Address Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
IADRH
This register is an alias of CSR2.
Read/Write accessible only when
either the STOP or the SPND bit
is set.
CSR18: Current Receive Buffer Address Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CRBAL
Contains the lower 16 bits of the
current receive buffer address at
which
the
Am79C975 controller will store
incoming frame data.
Am79C973/
Read/Write accessible only when
either the STOP or the SPND bit
is set. These bits are unaffected
by H_RESET, S_RESET, or
STOP.
CSR19: Current Receive Buffer Address Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CRBAU
Contains the upper 16 bits of the
current receive buffer address at
which
the
Am79C975 controller will store
incoming frame data.
Am79C973/
Read/Write accessible only when
either the STOP or the SPND bit
is set. These bits are unaffected
by H_RESET, S_RESET, or
STOP.
CSR20: Current Transmit Buffer Address Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CXBAL
Contains the lower 16 bits of the
current transmit buffer address
from which the Am79C973/
Am79C975 controller is transmit-
ting.
Read/Write accessible only when
either the STOP or the SPND bit
is set. These bits are unaffected
by H_RESET, S_RESET, or
STOP.
CSR21: Current Transmit Buffer Address Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CXBAU
Contains the upper 16 bits of the
current transmit buffer address
from which the Am79C973/
Am79C975 controller is transmit-
ting.
Read/Write accessible only when
either the STOP or the SPND bit
is set. These bits are unaffected
by H_RESET, S_RESET, or
STOP.
CSR22: Next Receive Buffer Address Lower
Bit
Name
Description
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15-0 NRBAL
Contains the lower 16 bits of the
next receive buffer address to
which
the
Am79C975 controller will store
incoming frame data.
Am79C973/
Read/Write accessible only when
either the STOP or the SPND bit
is set. These bits are unaffected
by H_RESET, S_RESET, or
STOP.
CSR23: Next Receive Buffer Address Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
NRBAU
Contains the upper 16 bits of the
next receive buffer address to
which
the
Am79C975 controller will store
incoming frame data.
Am79C973/