MU9C8338A 10/100Mb Ethernet Filter Interface
Software Model
Built-In Routines
Initiate Set Address Sequence
The MU9C8338A contains a series of built-in routines that
can be invoked or triggered by writing any arbitrary value
to the appropriate System Command register. There are
five built-in routines that can be used to perform general
system management functions. Additionally there are two
other routines that are used to alter the data-age gap
between the two time stamp counters. Details of the
built-in routines that are performed when invoked can be
found in Applications: Built-In Routines. Details of the
appropriate register for each routine can be found in
Operational Characteristics: Software Model-System
Registers. The following explains the steps that are
required when using each of the seven routines:
1. Write the desired address of the CAM entry to be read
into SCDW0.
2. Initiate the set address sequence by writing any value to
the SDO_SETADD register.
Note: This sequence should be initiated prior to the read entry
sequence being initiated in order to specify the address that
should be read.
Initiate Read Entry Sequence
The Read Entry Sequence should only be used for
diagnostic purposes when the MU9C8338A is not
processing Source or Destination addresses. Therefore, if
the user must read entries while packets are being
processed, the SA and DA processing functions should be
disabled prior to invoking the sequence. Once the entry
has been read, the SA and DA processing functions should
be enabled to return the MU9C8338A to normal.
Increment the Current Time Stamp
Initiates the STCURR increment sequence by writing any
arbitrary value to SDO_INCTS.
Increment the Purge Time Stamp
Initiates the STPURG increment sequence by writing any
arbitrary value to SDO_INCPR.
1. Write the Page Address to the CAM device to be read
into SCDW0. This should match the value that was
configured during any CAM configuration routine.
Increment the Current Time Stamp and Purge Time
Stamp
2. Initiate the read entry sequence by writing any value to
the SDO_READ register.
Initiates the STCURR and STPURG increment sequence
by writing any arbitrary value to SDO_INCTSPR.
3. The specified entry can be read from SCDW3, 2, and 1
and the associated data can be read from SCDW0. Bits
47–32 should be read from SCDW 3, bits 31–16 from
SCDW2, and bits 15–0 from SCDW1.
Initiate Delete Sequence
1. Write the address to be deleted into System Command
Data Word (SCDW) 2, 1, and 0. Bits 47–32 should be
written into SCDW 2, bits 31–16 into SCDW1, and bits
15–0 into SCDW0.
4. The CAM Status Register bits 31–16 associated with
the entry can be read from the System CAM Status
Word B (SCSWB) register.
2. Initiate the delete sequence by writing any value to the
SDO_DELETE register.
5. The CAM Status Register bits 15–0 associated with the
entry can be read from the System CAM Status Word A
(SCSWA) register.
Initiate Add Sequence
1. Write the address to be added into System Command
Data Word (SCDW) 3, 2, and 1. Bits 47–32 should be
written into SCDW 3, bits 31–16 into SCDW2, and bits
15–0 into SCDW1.
Note: This sequence should be initiated in conjunction with the
set address sequence in order to specify the address that should
be read. If successive entries are to be read, SDO_SETADD is
used only once as the CAM Address register will increment
automatically.
2. Write the associated data for this entry into SCDW0.
The port ID should be set in bits 13–8 and bit 15 should
be set HIGH if the entry is to be permanent.
3. Initiate the add sequence by writing any value to the
SDO_ADD register.
18
Rev. 0a
MUSIC [ MUSIC SEMICONDUCTORS ]
