Reed-Solomon II IP Core User Guide

ID 683144
Date 5/02/2016
Public

3.3.2. Reed-Solomon II IP Core Signals

Table 7.  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 asynchronously. 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 8.   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: [in_numn,in_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
  • in_data[15:0] = numn
in_channel channel Input Specifies the channel number for data the IP core transfers on the current cycle. The in_channel signal is available only when you configure the IP core to support multiple channels.
in_startofpacket sop Input Start of packet (codeword) signal.
in_endofpacket eop Input End of packet (codeword) signal.
in_error error Input Error signal. Specifies if the input data symbol is an error and whether the decoder can consider it as an erasure. Erasures-supporting decoders only.
out_startofpacket sop Output Start of packet (codeword) signal. This signal indicates the codeword boundaries on the in_data[] bus. When the IP core drives this signal high, it indicates that the start of packet is present on the in_data[] bus. The IP core asserts this signal on the first transfer of every codeword.
out_endofpacket eop Output End of packet (codeword) signal. This signal indicates the packet boundaries on the in_data[] bus. When the IP core drives this signal high, it indicates that the end of packet is present on the in_data[] bus. The IP core asserts this signal on the last transfer of every packet.
out_ready ready Input Data transfer ready signal to indicate that the downstream module is ready to accept data. The source provides new data (if available) when you assert the out_ready signal and stops providing new data when you deassert the out_ready signal. If the source is unable to provide new data, it deasserts out_valid for one or more clock cycles until it is prepared to drive valid data interface signals.
out_valid valid Output Data valid signal. The IP core asserts the out_valid signal high, whenever a valid output is on out_data ; the IP core deasserts the signal when there is no valid output on out_data .
out_data data Output Contains decoded output when the IP core asserts the out_valid signal. The corrected symbols are in the same order that they are entered.
out_channel channel Output Specifies the channel whose result is presented at out_data . Available only when you configure the IP core to support multiple channels.
out_error error Output Indicates non-correctable codeword (decoder only). Valid when the IP core asserts out_endofpacket .
Table 9.   Configuation Signals
Name Direction Description
num_check Output Sets the variable number of check symbols up to a maximum value set by the parameter R (variable option only).
numn Output Variable value of N. Can be any value from the minimum allowable value of N up to the selected value of N (variable and erasures-supporting option only).
Table 10.   Status Interface Signals
Name Avalon-ST Type Direction Description
status_error_value conduit Output Error correction value for every valid data symbol.
status_num_error_symbol conduit Output Number of error symbols in a codeword. This signal is valid when the IP core asserts out_endofpacket . Only available when you turn on Error symbol count .
status_num_error_bit conduit Output Number of error bits in a codeword. This signal is valid when the IP core asserts the out_endofpacket . Only available when you turn on Error bit count and select Full for Error bits count format .
status_num_error_bit0 conduit Output Number of bit errors for the correction from bit 1 to bit 0. The latest is the correct bit. This signal is valid when the IP core asserts the out_endofpacket . Only available when you turn on Error bit count and select Split for Error bits count format .
status_num_error_bit0 conduit Output Number of bit errors for the correction from bit 0 to bit 1. The latest is the correct bit. This signal is valid when the IP core asserts the out_endofpacket . Only available when you turn on Error bit count and select Split for Error bits count format .

Did you find the information on this page useful?

Characters remaining:

Feedback Message