Configuration Tab - 2.0 English

Clock Frequency (MHz)

Specifies the frequency of s_axis_aclk, in MHz. If set to 30.72 multiplied by a power of two and operated at that clock frequency, the DFE PRACH core will maintain a 10 ms radio frame. Setting to a non-power of two less than 491.52 MHz will result in radio frame which is longer than 10 ms in duration. Using a value greater than 491.52MHz will result in a shorter frame duration.

Number of Bands Required

The core can provide PRACH processing for up to three separate bands. This parameter specifies the number required. For replacement of legacy cores, one band should be selected. A Band Configuration Tab will open for each requested band.

Maximum RACH per Antenna

This parameter sets the maximum number of RACH channels that can be processed simultaneously by the core. Valid values are 1-16. Reducing this number allows efficient use of logic fabric resources within the core.

Number of Output Lanes Required

The core can be configured to output PRACH captures on one or two output lanes. The number of output lanes affects how capture samples are allocated to the PRACH output. The number of lanes available is restricted by the Number of Antennas configured on each active band. If eight antennas are configured on any band, the number or output lanes must be two. If one antenna is configured on any band, the number of output lanes must be one. All other configurations can select 1 or 2 lanes.

Sample Width In

The number of bits used to represent the I and Q components of the input data samples. Switchable between 16 (the default) and 18 bits. The Sample Width applies across all enabled bands.

Remove Internal Scheduling

This parameter determines if the core includes hardware to track the location of the PRACH captures within the radio frame. If set, it will remove the hardware which schedules PRACH channels and they will instead operate continually, based only on their configured channel mapping, demodulation and decimation. In this mode, it is your responsibility to extract the preamble from the output stream of RACH channel samples. If left unchecked, the core will behave as in previous releases and maintain an internal static or dynamic schedule which is used to specify the location of the capture within the radio frame.

Enable Dynamic Schedule

This parameter determines whether or not the dynamic scheduling logic and associated AXI4-Stream scheduling control interface is included in the core. By default this logic is not included. This parameter cannot be set if the "Remove Internal Scheduling" option is selected.

IRQ Output

Determines whether the core should include an IRQ output port to connect with the interrupt controller of the microprocessor. By default, no IRQ output port is provided.

All active bands will have their own configuration tab. The parameters on each tab are identical.

Number of Antennas

The core can provide PRACH processing for up to eight antennas in parallel, per band. This selects the number of antennas for this band. Selecting one antenna on one band and eight antennas on a different band is not permitted. All other antenna selections are allowed.

Antenna Interleave

This factor specifies the number of clock cycles across which the samples for each antenna are transferred for this band. For example, if the number of antennas is set to 4, an antenna interleave of one transfers the data for all four antennas in parallel in a single clock cycle. At the other extreme, an antenna interleave of four transfers the data for a single antenna on each clock cycle, and it takes four cycles in total to transfer the data for all antennas. The antenna interleave cannot be larger than the number of antennas on this band. An antenna interleave of one is not supported when eight antennas are in use.

Maximum Useable CCs

This parameter sets the maximum number of component carriers for this band that can be processed simultaneously by the core. Valid values are 2, 4, 8, and 16, depending on the antenna interleave for this band. The product of the antenna interleave and the maximum number of useable CCs cannot exceed 16. Reducing this number allows efficient use of logic fabric resources within the core.

TUSER Width

The number of bits per sample on the TUSER input for this band. Each band has its own TUSER to allow per band Frame initialization. TUSER for each band is propagated to the m_axis_tbase_tuser port. The port contains a delayed version of each TUSER input, concatenated into a single sample. The m_axis_tbase_tuser bus has a width equal to the sum of TUSER width for all active bands. Valid values are 1 up to 64 bits. The default is eight bits. Different bands can have different values.