P R E L I M I N A R Y
AMD
129
Am79C970A
CSR33: Next Transmit Descriptor Address Upper
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the upper 16 bits of
the next transmit descriptor
address pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0 NXDAU
only
CSR34: Current Transmit Descriptor Address
Lower
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the lower 16 bits of the
current
transmit
address pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0
CXDAL
descriptor
only
CSR35: Current Transmit Descriptor Address
Upper
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the upper 16 bits of the
current transmit descriptor ad-
dress pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0 CXDAU
only
CSR36: Next Next Receive Descriptor Address
Lower
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the lower 16 bits of the
next next receive descriptor
address pointer.
15–0 NNRDAL
Read/Write
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
accessible
only
CSR37: Next Next Receive Descriptor Address
Upper
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the upper 16 bits of the
next next receive descriptor
address pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0 NNRDAU
only
CSR38: Next Next Transmit Descriptor Address
Lower
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the lower 16 bits of the
next next transmit descriptor
address pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0 NNXDAL
only
CSR39: Next Next Transmit Descriptor Address
Upper
Bit
Name
Description
31–16
RES
Reserved locations. Written as
ZEROs and read as undefined.
Contains the upper 16 bits of the
next next transmit descriptor
address pointer.
Read/Write
accessible
when either the STOP or the
SPND bit is set. These bits
are unaffected by H_RESET,
S_RESET or by setting the
STOP bit.
15–0 NNXDAU
only