The xwr_streamers.vhd module (located in modules/wr_streamers folder
provides a WR PTP Core -compatible communication. It is
meant to be a used as a building block in WR-based nodes. Additionally to transmission and reception of data, it provides advanced
diagnostics and debugging capabilities that can be accessed via SNMP and
WB registers (via PCI or VME).
The xwr_streamers.vhd module includes the following sub-modules:
WB config and status register (wr_streamers_wb.vhd)
Interface of the xwr_streamers.vhd module
g_streamers_op_mode - Indicates whether this module instantiates
both TX and RX streamers (set to TX_AND_RX) or only one
of them. An application that only receives or only transmits might want
to use RX_ONLY or TX_ONLY mode in order to save resources.
g_clk_ref_rate - the rate of the White Rabbit reference clock. By default, this clock is
125MHz for WR Nodes. There are some WR Nodes that work with 62.5MHz.
g_tx_streamer_params - Tx streamer generics stored in one record:
data_width, buffer_size, threshold, max_words_per_frame, timeout,
escape_code_disable, use_ref_clk_for_data - they map into Transmit Streamer module generics
described in detail in Transceiver configuration.
g_rx_streamer_params - Rx streamer generics stored in one record:
data_width, buffer_size, escape_code_disable,
expected_words_number, use_ref_clk_for_data - they map into Receive Streamer module generics
described in detail in Transceiver
configuration for details.
g_stats_cnt_width - Width of statistics counters: frame
rx/tx/lost, block lost, counter of accumuted latency (minimum 15 bits,
g_stats_acc_width - Width of latency accumulator (max value 64).
g_slave_mode - Specifies wishbone interface mode.
g_slave_granularity - Set wishbone address granularity.
g_simulation - If set to 1, the module is run in simulation mode and some
processes can be made to take less time.
g_sim_cycle_counter_range - Indicates (shortened) duration of second to see TAI seconds counter increment,
for simulation only (i.e. only if g_simulation = 1).
Wishbone-based access that can be used to overrite the Direct network configuration (i.e. tx_streamer_cfg_i and rx_streamer_cfg_i) and to read streamers statistics for diagnostics,
it is located in the address-space of WR PTP Core (offset 0x20700), the
WB memory map.
32-bit array that is used by the WR PTP Core to read streamers statistics for diagnostics, WR PTP Core exposes these data via SNMP and shell interface (command diag)