Altera Reed-Solomon II MegaCore Function User Manual
Page 24
Table 3-3: Clock and Reset Signals
Name
Avalon-ST Type
Direction
Description
clk_clk
clk
Input
The main system clock. The whole IP core operates
on the rising edge of
clk_clk
.
reset_
reset_n
reset_n
Input
An active low signal that resets the entire system
when asserted. You can assert this signal asynchro‐
nously. However, you must deassert it synchronous
to the
clk_clk
signal. When the IP core recovers
from reset, ensure that the data it receives is a
complete packet.
Table 3-4: Avalon-ST Input and Output Interface Signals
Name
Avalon-ST Type
Direction
Description
in_ready
ready
Output
Data transfer ready signal to indicate that the sink is
ready to accept data. The sink interface drives the
in_ready
signal to control the flow of data across
the interface. The sink interface captures the data
interface signals on the current
clk
rising edge.
in_valid
valid
Input
Data valid signal to indicate the validity of the data
signals. When you assert the
in_valid
signal, the
Avalon-ST data interface signals are valid. When
you deassert the
in_valid
signal, the Avalon-ST
data interface signals are invalid and must be
disregarded. You can assert the
in_valid
signal
whenever data is available. However, the sink only
captures the data from the source when the IP core
asserts the
in_ready
signal.
in_data[]
data
Input
Data input for each codeword, symbol by symbol.
Valid only when you assert the
in_valid
signal. For
Qsys systems, the
in_data
bus is:
[
numn
,
numcheck
,
data
] If you have no variable check
it is: [
numn
,
data
]
For example, for a maximum codeword length of
255 corresponding to 8 bits:
•
in_data[7:0]
=
data
•
indata_[15:0]
=
numn
in_channel
channel
Input
Specifies the channel number for data the IP core
transfers on the current cycle. The
in_channe
l
signal is available only when you configure the IP
core to support multiple channels.
in_startof-
packet
sop
Input
Start of packet (codeword) signal.
in_
endofpacket
eop
Input
End of packet (codeword) signal.
3-8
Reed-Solomon II IP Core Signals
UG-01090
2015.05.01
Altera Corporation
Reed-Solomon II IP Core Functional Description