Turbo Intel® FPGA IP User Guide

ID 683734
Date 4/01/2024
Public
Document Table of Contents

4.3.

Signal names beginning with sink_* are the input interface to the Turbo IP. Signal names beginning with source_* are the output interface from the Turbo IP (excluding sink_ready and source_ready signals). Both interfaces comply with the Avalon Streaming specification with READY_LATENCY = 0.
Table 17.  Turbo Encoder Signals
Signal Direction Description
clk Input Clock signal that clocks all internal registers.
reset_n Input Active low reset signal. The IP core must always be reset before receiving data. If the megafunction is not reset, the Turbo encoder may produce unexpected results because of feedback signals.
sink_blk_size Input Specifies the incoming block size. This needs to be held throughout the whole incoming block, from sop to eop.
sink_data Input Input data.
sink_eop Input Indicates the end of an incoming packet.
sink_sop Input Indicates the start of an incoming packet.
sink_valid Input Asserted when data atsink_data is valid. When you deassert sink_valid, the IP core stops processing until you reassert sink_valid.
source_ready Input Asserted by the downstream module if it cannot accept data.
sink_ready Output Indicates when the IP core can accept data.
source_blk_size Output Specifies the outgoing block size K.

Valid at source_sop.

source_data_s Output Output data.
source_eop Output Indicates the end of an outgoing packet.
source_sop Output Indicates the start of an outgoing packet.
source_valid Output Asserted by the IP core when valid data is available to output.
Table 18.  Turbo Decoder Signals
Signal Direction Description
clk Input Clock signal that clocks all internal registers.
reset_n Input Active low reset signal. You must always reset the IP core before it receives data. If not reset, the Turbo decoder may produce unexpected results because of feedback signals.
CRC_pass Output

Indicates whether CRC was successful:

  • 0: Fail
  • 1: Pass
Note: This signal is present only in LTE mode.
CRC_type Output

Indicates the type of CRC that was used for the current data block:

  • 0: CRC24A
  • 1: CRC24B
Note: This signal is present only in LTE mode.
sel_CRC24A Input

Specifies the type of CRC that you need for the current data block:

  • 0: CRC24A
  • 1: CRC24B
Note: This signal is present only in LTE mode.
sink_blk_size Input Specifies the incoming block size. This signal needs to be held throughout the whole incoming block from SOP to EOP.
sink_data Input Input data.
sink_eop Input Indicates the end of an incoming packet.
sink_max_iter Input Specifies the maximum number of half-iterations. It must be even numbers for UMTS.
sink_ready Output Indicates when the IP core can accept data.
sink_sop Input Indicates the start of an incoming packet.
sink_valid Input Assert when data at sink_data is valid. When sink_valid is not asserted, processing stops until you reassert sink_valid.
source_blk_id Output Specifies the outgoing block ID.
source_blk_size Output Specifies the outgoing block size.
source_data_s Output Output data.
source_eop Output Indicates the end of an outgoing packet.
source_iter Output Shows the number of half iterations after which the Turbo decoder stops processing the current data block. LTE only.
source_ready Input Asserted by the downstream module if it can accept data.
source_sop Output Indicates the start of an outgoing packet.
source_valid Output Asserted by the IP core when there is valid data to output.

Signals in Platform Designer (Standard) Systems

Platform Designer (Standard) systems instantiate all Turbo IP core signals as part of the Avalon-ST data bus.

Table 19.  Turbo Encoder Data Input
Bits Signal
N enc + 12:N enc sink_blk_size
N enc -1:0 sink_data
Table 20.  Turbo Encoder Data Output
Bits Signal
3 *N enc+12:3*N enc source_blk_size
3*N enc-1:0 source_data
Table 21.  Turbo Decoder Data InputIW is the number of bits for input precision.
Bits Signal
3*WLLR*NLLR+18 Sel_CRC24A (LTE only)
3*WLLR*NLLR+17:3*WLLR*NLLR+13 sink_max_iter
3*WLLR*NLLR+12:3*WLLR*NLLR sink_blk_size
3*WLLR*NLLR-1:0 sink_data
Table 22.  LTE Turbo Decoder Data Output
Bits Signal
Wout+19 CRC_Pass
Wout+18 CRC_type
Wout+17:Wout+13 source_iter
Wout+12:Wout source_blk_size
Wout-1:0 source_data
Table 23.  UMTS Turbo Decoder Data Output
Bits Signal
13:1 source_blk_size
0 source_data