Table 8-8: Avalon-MM Bidirectional Port Signals
Function
Direction
Bits
Name
Clock for the Avalon-MM interface
In
1
clk
Indicates read transaction
In
1
read
Indicates write transaction
In
1
write
Address of the transaction
In
32
address
Read data return
Out
32, 64, 128, or 256
readdata
Valid cycle flag for read data return
Out
1
readdatavalid
Write data for a transaction
In
32, 64, 128, or 256
writedata
Byte enables for each write byte
In
4 (32-bit data), 8(64-bit
data), 16(128-bit data),
32(256-bit data)
byteenable
Indicates need for additional cycles to
complete a transaction
Out
1
waitrequest
Transaction burst length
In
11
burstcount
The read and write interfaces are configured to the same size. The byte-enable size scales with the data bus
size.
Related Information
Avalon Interface Specifications
Information about the Avalon-MM protocol
Avalon-MM Write Port
The Avalon-MM write ports are standard Avalon-MM ports used only to dispatch write operations. Each
configured Avalon-MM write port consists of the signals listed in the following table.
SDRAM Controller Subsystem
Altera Corporation
cv_54008
Avalon-MM Write Port
8-18
2013.12.30