ACD82124 Datasheet, PDF (44/48 Pages) List of Unclassifed Manufacturers – 24 Ports 10/100 Fast Ethernet Switch Controller

5. REGISTER DESCRIPTION
ACD80800 provides a bunch of registers for the CPU
to access the address table inside it. Command is sent
to ACD80800 by writing into the associated registers.
Before the CPU can pass a command to ACD80800,
it must check the result register (register 11) to see if
the command has been done. When the Result regis-
ter indicates the command has been done, the CPU
may need to retrieve the result of previous command
first. After that, the CPU has to write the associated
parameter of the command into the Data registers.
Then, the CPU can write the command type into the
command register. When a new command is written
into the command register, ACD80800 will change the
status of the Result register to 0. The Result register
will indicate the completion of the command at the end
of the execution. Before the completion of the execu-
tion, any command written into the command register
is ignored by ACD80800.
The registers accessible to the CPU are described by
table-2:
Table-2: Register Description
Reg.
Name
Description
0 DataReg0
Byte 0 of data
1 DataReg1
Byte 1 of data
2 DataReg2
Byte 2 of data
3 DataReg3
Byte 3 of data
4 DataReg4
Byte 4 of data
5 DataReg5
Byte 5 of data
6 DataReg6
Byte 6 of data
7 DataReg7
Byte 7 of data
8 AddrReg0
LSB of address value
9 AddrReg1
MSB of address value
10 CmdReg
Command register
11 RsltReg
Result register
12 CfgReg
Configuration register
13 IntSrcReg
Interrupt source register
14 IntMskReg
Interrupt mask register
15 nLearnReg0
Address learning disable
register for port 0 - 7
16 nLearnReg1
17 nLearnReg2
Address learning disable
register for port 8 - 15
Address learning disable
register for port 16 - 23
18 AgeTimeReg0 LSB of aging period register
19
AgeTimeReg1
MSB of aging period
register
20 PosCfg
Power On Strobe
configuration register 0
The DataRegX are registers used to pass the param-
eter of the command to the ACD80800, and the result
of the command to the CPU.
The AddrRegX are registers used to specify the ad-
dress associated with the command.
The CmdReg is used to pass the type of command to
the ACD80800. The command types are listed in table-
3. The details of each command is described in the
chapter of “Command Description.”
Table-3: Command List
Command
Description
0x09
0x0A
0x0B
0x0C
0x0D
Add the specified MAC address into the
address table
Set a lock for the specified MAC
address
Set a filtering flag for the specified MAC
address
Delete the specified MAC address from
the address table
Assign a port ID to the specified MAC
address
0x10
Read the first entry of the address table
0x11
Read next entry of address book
0x20
Read first valid entry
0x21
Read next valid entry
0x30
Read first new page
0x31
Read next new page
0x40
Read first aged page
0x41
Read next aged page
0x50
Read first locked page
0x51
Read next locked page
0x60
Read first filtered page
0x61
Read next filtered page
0x80
Read first page with specified PID
0x81
Read next page with specified PID
0xFF
System reset
The RstReg is used to indicate the status of command
execution. The result code is listed as follows:
• 01 - command is being executed and is
not done yet
• 10 - command is done with no error
• 1x - command is done, with error indi-
cated by x, where x is a 4-bit error code:
0001 for cannot find the entry as speci-
fied
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