am79c961 Advanced Micro Devices, am79c961 Datasheet - Page 85

• Manufacturer Part Number: am79c961
• Description: Pcnettm-isa Jumperless Single-chip Ethernet Controller For Isa
• Manufacturer: Advanced Micro Devices

CSR44-45: Next Receive Status and Byte Count
Bit
31-24 NRST
23-12
11-0
CSR46: Poll Time Counter
Bit
15-0
CSR47: Polling Interval
Bit
31-16
15-0 POLLINT
NRBC
POLL
Name
Name
Name
RES
RES
Read/write accessible only when
STOP bit is set.
Next Receive Status. This field is
a copy of bits 15:8 of RMD1 of the
next receive descriptor.
Read/write accessible only when
STOP bit is set.
Reserved locations. Written as
zero and read as undefined.
Next Receive Byte Count. This
field is a copy of the BCNT field of
RMD2 of the next receive
descriptor.
Read/write accessible only when
STOP bit is set.
Poll Time Counter. This counter
is
PCnet-ISA
and is used to trigger the descrip-
tor ring polling operation of the
PCnet-ISA
Read/write accessible only when
STOP bit is set.
Reserved locations. Written as
zero and read as undefined.
Polling Interval. This register
contains
PCnet-ISA
between successive polling op-
erations. The POLLINT value is
expressed as the two’s comple-
ment of the desired interval,
where each bit of POLLINT rep-
resents one-half of an XTAL1
period of time. POLLINT[3:0] are
ignored. (POLINT[16] is implied
to be a one, so POLLINT[15] is
significant, and does not repre-
sent the sign of the two’s
complement POLLINT value.)
The default value of this register
is 0000. This corresponds to a
incremented
Description
Description
Description
+
+
+
the
controller microcode
controller.
controller will wait
time
by
that
P R E L I M I N A R Y
Am79C961
the
the
CSR48-49: Temporary Storage
Bit
31-0
CSR50-51: Temporary Storage
Bit
31-0
CSR52-53: Temporary Storage
Bit
31-0
CSR54-55: Temporary Storage
Bit
31-0
TMP0
TMP1
TMP2
TMP3
Name
Name
Name
Name
polling interval of 32,768 XTAL1
periods. The POLINT value of
0000 is created during the
microcode initialization routine,
and therefore might not be seen
when
RESET.
If the user desires to program a
value for POLLINT other than the
default, then the correct proce-
dure is to first set INIT only in
CSR0. Then, when the initializa-
tion sequence is complete, the
user must set STOP in CSR0.
Then the user may write to
CSR47 and then set STRT in
CSR0. In this way, the default
value of 0000 in CSR47 will be
overwritten with the desired user
value.
Read/write accessible only when
STOP bit is set.
Temporary Storage location.
Read/write accessible only when
STOP bit is set.
Temporary Storage location.
Read/write accessible only when
STOP bit is set.
Temporary Storage location.
Read/write accessible only when
STOP bit is set.
Temporary Storage location.
Read/write accessible only when
STOP bit is set.
reading
Description
Description
Description
Description
CSR47
AMD
1-559
after