136
Am79C965A
H_RESET or S_RESET and is
unaffected by the STOP bit.
1
DTX
Disable Transmit results in PCnet-32
controller not accessing the
Transmit Descriptor Ring and
therefore no transmissions are
attempted. DTX =
“
0
”
, will set TXON
bit (CSR0 bit 4) if STRT (CSR0 bit 1)
is asserted.
Read/write accessible only when
STOP bit is set.
0
DRX
Disable
PCnet-32 controller not accessing
the Receive Descriptor Ring and
therefore all receive frame data are
ignored. DRX =
“
0
”
, will set RXON
bit (CSR0 bit 5) if STRT (CSR0 bit 1)
is asserted.
Receiver
results
in
Read/write accessible only when
STOP bit is set.
CSR16: Initialization Block Address Lower
Bit
Name
Description
This register is an alias of the lo-
cation CSR1. Accesses to/from this
register are equivalent to access to
CSR1.
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15-0
IADR
Lower 16 bits of the address of the
Initialization Block. This register is
an alias of CSR1. Whenever this
register is written, CSR1 is updated
with CSR16
’
s contents.
Read/Write accessible only when
the STOP bit in CSR0 is set.
Unaffected by RESET.
CSR17: Initialization Block Address Upper
Bit
Name
Description
This register is an alias of the lo-
cation CSR2. Accesses to/from this
register are equivalent to access to
CSR2.
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15-0
IADR
Upper 16 bits of the address of the
Initialization Block. This register is
an alias of CSR2. Whenever this
register is written, CSR2 is updated
with CSR17
’
s contents.
Read/Write accessible only when
the STOP bit in CSR0 is set.
Unaffected by RESET.
CSR18: Current Receive Buffer Address Lower
Bit
Name
Description
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CRBA
Contains the lower 16 bits of the
current receive buffer address at
which the PCnet-32 controller will
store incoming frame data.
Read/write accessible only when
STOP 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
CRBA
Contains the upper 16 bits of the
current receive buffer address at
which the PCnet-32 controller will
store incoming frame data.
Read/write accessible only when
STOP 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
CXBA
Contains the lower 16 bits of the
current transmit buffer address from
which the PCnet-32 controller is
transmitting.
Read/write accessible only when
STOP bit is set.
CSR21: Current Transmit Buffer Address Upper
Bit
Name
Description
31-16 RES
Reserved locations. Written as
zeros and read as undefined.
15-0
CXBA
Contains the upper 16 bits of the
current transmit buffer address from
which the PCnet-32 controller is
transmitting.
Read/write accessible only when
STOP bit is set.