AMD
P R E L I M I N A R Y
136
Am79C965
CSR36: Next Next Receive Descriptor Address
Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0 NNRDA
Contains the lower 16 bits of the
next next receive descriptor ad-
dress pointer.
Read/write accessible only when
STOP bit is set.
CSR37: Next Next Receive Descriptor Address
Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0 NNRDA
Contains the upper 16 bits of the
next next receive descriptor ad-
dress pointer.
Read/write accessible only when
STOP bit is set.
CSR38: Next Next Transmit Descriptor Address
Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
NNXDA
Contains the lower 16 bits of the
next next transmit descriptor ad-
dress pointer.
Read/write accessible only when
STOP bit is set.
CSR39: Next Next Transmit Descriptor Address
Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-0
NNXDA
Contains the upper 16 bits of the
next next transmit descriptor ad-
dress pointer.
Read/write accessible only when
STOP bit is set.
CSR40: Current Receive Status and Byte Count
Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-12
RES
Reserved locations. Read and
written as zero.
11-0
CRBC
current Receive Byte Count. This
field is a copy of the BCNT field of
RMD2 of the current receive de-
scriptor.
Read/write accessible only when
STOP bit is set.
CSR41: Current Receive Status and Byte Count
Upper
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-8
CRST
Current Receive Status. This
field is a copy of bits 15:8 of
RMD1 of the current receive de-
scriptor.
Read/write accessible only when
STOP bit is set.
7-0
RES
Reserved locations. Read and
written as zero.
CSR42: Current Transmit Status and Byte Count
Lower
Bit
Name
Description
31-16
RES
Reserved locations. Written as
zeros and read as undefined.
15-12
RES
Reserved locations. Read and
written as zero.
11-0
CXBC
current Transmit Byte Count.
This field is a copy of the BCNT
field of TMD2 of the current trans-
mit descriptor.
Read/write accessible only when
STOP bit is set.