am79c850 Advanced Micro Devices, am79c850 Datasheet - Page 52

• Manufacturer Part Number: am79c850
• Description: Supernet-r 3
• Manufacturer: Advanced Micro Devices

52
AMD
INST 2:0
000
001
010
011
100
101
110
111
Invalidate CAM: This function invalidates all entries in the CAM. The DONE, FULL, FOUND,
MULT, ERROR, BISTDONE and EXACT bits in the status register will be cleared when this com-
mand is issued. The DONE and EMPTY bits in the status register will be set upon completion of this
operation.
Write CAM: This function writes the contents of the comparand, mask and personality registers into
an empty location in the CAM. The DONE, FULL, FOUND, MULT, BISTDONE and EXACT bits in
the status register will be cleared when this command is issued. The DONE bit in the status register
will be set upon completion of this operation. The FULL bit in the status register will be set if the CAM
is full when this operation is completed. If the FULL bit is set when this command is issued, the write
operation will not be performed and the ERROR bit in the status register will be set. Otherwise, the
ERROR bit will be cleared.
Read CAM: This function causes the contents of the CAM entry matching the comparand (indi-
cated by the FOUND bit in the status register after a FIND command) to be written to the comparand,
mask and personality registers in the node processor interface. If more than one entry matches the
comparand (indicated by the MULT bit in the status register), one of the entries will be chosen arbi-
trarily. The DONE, FOUND, MULT, ERROR, BISTDONE and EXACT bits in the status register will
be cleared when this command is issued. Upon completion of this operation, the DONE bit in the
status register will be set. The ERROR bit will be set if this operation is attempted while the CAM is
empty or if the FOUND bit is not set.
Run BIST: This function causes the AF to initiate its built-in self test. The contents of the CAM, in-
cluding all of its registers, may be modified by the operation of this self test. The DONE, FOUND,
MULT, ERROR, BISTDONE and EXACT bits in the status register will be cleared when this com-
mand is issued. Upon completion of this operation, the DONE and BISTDONE bits in the status reg-
ister will be set. Other status bits may be in arbitrary states. The AF must be reset after BIST is com-
pleted to return it to a known state before performing any other operations on the AF.
Find: This function causes the AF to perform a parallel comparison of the comparand registers with
the contents of the CAM. CAM entries that have the SKIP bit set will not match the comparand. The
node processor mask registers do not participate in this operation. The DONE, FOUND, MULT, ER-
ROR, BISTDONE and EXACT bits in the status register will be cleared when this command is is-
sued. Upon completion of this operation, the DONE bit in the status register will be set and the
FOUND, MULT and EXACT bits will be updated with the appropriate status of the operation.
Invalidate: This function operates on the result of the last “Find” instruction, above, and sets the
INVALID bit in the personality of the first matching entry in the CAM. The DONE, FOUND, MULT,
ERROR, BISTDONE and EXACT bits in the status register will be cleared when this command is
issued. Upon completion of this operation, the DONE bit in the status register will be set. The
EMPTY bit will be updated with the appropriate status after the operation. The ERROR bit will be set
if this operation is attempted while the FOUND bit is not set. Otherwise, the ERROR bit will remain
cleared.
Skip: This function operates on the result of the latest “Find” operation and causes the AF to set the
SKIP bit in the personality of the first matching CAM entry. The SKIP bit will be set in the same entry
that will be read by issuing a “Read CAM” instruction. The DONE, FOUND, MULT, ERROR,
BISTDONE and EXACT bits in the status register will be cleared when this command is issued.
Upon completion of this operation, the DONE bit in the status register will be set. The ERROR bit will
be set if this operation is attempted while the FOUND bit is not set. Otherwise, the ERROR bit will
remain cleared.
Clear all SKIP bits: This function causes the CAM to clear all SKIP bits. The DONE, FOUND,
MULT, ERROR, BISTDONE and EXACT bits in the status register will be cleared when this com-
mand is issued. Upon completion of this operation, the DONE bit in the status register will be set.
P R E L I M I N A R Y
SUPERNET 3
Function