Changes between Initial Version and Version 1 of WARPLab/Reference/Baseband/Buffers

Timestamp:

May 15, 2013, 5:07:14 PM (11 years ago)

Author:

chunter

Comment:

--

WARPLab/Reference/Baseband/Buffers

@@ +1 @@
+[[TracNav(WARPLab/TOC)]]
+
+= Baseband Buffers Module Implementation =
+
+The WARPLab Reference Design implements a [wiki:../../Framework/Modules#Baseband Baseband] module that buffers incoming and outgoing samples from radio interfaces. It supports up to 4 interfaces, including both I/Q and RSSI. On WARP v3 hardware, each buffer is 2^15 samples long. On WARP v2 hardware, each buffer is 2^14 samples long.
+
+= Baseband Commands =
+
+Baseband commands are selected as string inputs to the {{{wl_basebandCmd}}} method in [browser:ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Reference/classes/wl_node.m wl_node.m]. These strings are each individual cases of the switch statement in {{{procCmd}}} method of [browser:ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Reference/classes/wl_baseband_buffers.m wl_baseband_buffers.m].
+
+== Syntax == 
+MATLAB allows two valid forms of syntax for calling methods
+
+ * Let {{{N}}} be a scalar or vector of {{{wl_node}}} objects
+ * Let {{{command_string}}} be a string containing a particular command
+ * Let {{{arg}}} be an argument for that command (optional)
+
+Syntax 1: {{{wl_basebandCmd(N, command_string, arg1, arg2, ..., argN)}}}
+
+Syntax 2: {{{N.wl_basebandCmd(command_string, arg1, arg2, ..., argN)}}}
+
+These two different forms of syntax are identical and either may be used for issuing commands to WARP nodes.
+
+=== Optional Buffer Selection Syntax ===
+
+Some baseband commands require the selection of one or more buffers. This requirement is specified in the below documentation with {{{Requires BUFF_SEL:}}}. If a command requires a buffer selection, then the following syntaxes are valid:
+
+ * Let {{{buffer_selection}}} be a collection of interfaces or the string {{{'RF_ALL'}}}
+
+Syntax 1: {{{wl_interfaceCmd(N, buffer_selection, command_string, arg1, arg2, ..., argN)}}}
+
+Syntax 2: {{{N.wl_interfaceCmd(buffer_selection, command_string, arg1, arg2, ..., argN)}}}
+
+
+== Command List and Documentation == 
+=== {{{tx_delay}}} ===
+Transmit delay- gets or sets the number of sample periods the baseband [[BR]]
+waits between the trigger and starting the transission[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none or (uint32 TX_DLY)
+
+'''Returns:''' (uint32 TX_DLY) or none
+
+If an argument is specified, this command enters a write mode where[[BR]]
+that argument is written to the board. If no argument is specified,[[BR]]
+the current value of TX_DLY is read from the board.[[BR]]
+
+
+=== {{{tx_length}}} ===
+Transmit length- reads or sets the duration of each transmit cycle, in sample periods [[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none or (uint32 TX_LEN)
+
+'''Returns:''' (uint32 TX_LEN) or none
+
+If an argument is specified, this command enters a write mode where[[BR]]
+that argument is written to the board. If no argument is specified,[[BR]]
+the current value of TX_LEN is read from the board.[[BR]]
+
+
+=== {{{rx_length}}} ===
+Receive length- reads or sets the duration of each receive cycle, in sample periods [[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none or (uint32 RX_LEN)
+
+'''Returns:''' (uint32 RX_LEN) or none
+
+If an argument is specified, this command enters a write mode where[[BR]]
+that argument is written to the board. If no argument is specified,[[BR]]
+the current value of RX_LEN is read from the board.[[BR]]
+
+
+=== {{{continuous_tx}}} ===
+Enable/disable continuous transmit mode[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' (boolean CONT_TX)
+CONT_TX:[[BR]]
+true enables continuous transmit mode[[BR]]
+false disable continuous transmit mode[[BR]]
+
+'''Returns:''' none
+
+
+=== {{{tx_buff_en}}} ===
+Enable transmit buffer for one or more interfaces. When a buffer is enabled it will[[BR]]
+drive samples into its associated interface when a trigger is received. The interface[[BR]]
+itself must also be enabled (wl_interfaceCmd(...,'tx_en')) to actually transmit the samples[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes
+
+'''Arguments:''' none
+
+'''Returns:''' none
+
+
+=== {{{rx_buff_en}}} ===
+Enable receive buffer for one or more interfaces. When a buffer is enabled it will[[BR]]
+capture samples from its associated interface when a trigger is received. The interface[[BR]]
+itself must also be enabled (wl_interfaceCmd(...,'rx_en'))[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes
+
+'''Arguments:''' none
+
+'''Returns:''' none
+
+
+=== {{{tx_rx_buff_dis}}} ===
+Disable the Tx and Rx buffers for one or more interfaces. When a buffer is disabled it will not[[BR]]
+output/capture samples when a trigger is received, even if the associated interface is enabled[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes
+
+'''Arguments:''' none
+
+'''Returns:''' none
+
+
+=== {{{tx_buff_clk_freq}}} ===
+Read the transmit sample clock frequency out of the buffer core.[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none
+
+'''Returns:''' (uint32 Fs_Tx)
+Fs_Tx: Tx sample frequency of buffer core in Hz[[BR]]
+
+
+=== {{{rx_buff_clk_freq}}} ===
+Read the receive sample clock frequency out of the buffer core.[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none
+
+'''Returns:''' (uint32 Fs_Rx)
+Fs_Rx: Rx sample frequency of buffer core in Hz[[BR]]
+
+
+=== {{{rx_rssi_clk_freq}}} ===
+Read the receive RSSI sample clock frequency out of the buffer core.[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' none
+
+'''Returns:''' (uint32 Fs_RxRSSI)
+Fs_RxRSSI: Rx RSSI sample frequency of buffer core in Hz[[BR]]
+
+
+=== {{{write_iq}}} ===
+Write I/Q samples to the specified buffers. The dimensions of the buffer selection and samples matrix[[BR]]
+must agree. The same samples can be written to multiple buffers by combining buffer IDs[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes (combined BUFF_SEL values ok)
+
+'''Arguments:''' (complex double TX_SAMPS, int OFFSET)
+TX_SAMPS: matrix of complex samples. The number of columns must match the length of BUFF_SEL[[BR]]
+OFFSET: buffer index of first sample to write (optional; defaults to 0)[[BR]]
+
+Examples:[[BR]]
+{{{
+TxLength = 2^14;
+Ts = 1/(wl_basebandCmd(node0,'tx_buff_clk_freq'));
+t = [0:Ts:(TxLength-1)*Ts].'; %column vector
+X = exp(t*1i*2*pi*3e6); %3MHz sinusoid
+Y = exp(t*1i*2*pi*5e6); %5MHz sinusoid
+
+%Write X to RFA
+wl_basebandCmd(node, RFA, 'write_iq', X);
+
+%Write X to RFA and RFB
+wl_basebandCmd(node, RFA+RFB, 'write_iq', X);
+
+%Write X to RFA, Y to RFB
+wl_basebandCmd(node, [RFA RFB], 'write_iq', [X Y]);
+}}}
+
+=== {{{read_iq}}} ===
+Read I/Q samples from the specified buffers. The elements of the buffer selection must be scalers which[[BR]]
+identify a single buffer. To read multiple buffers in one call, pass a vector of individual buffer IDs[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes (combined BUFF_SEL values not allowed)
+
+'''Arguments:''' (int OFFSET, int NUM_SAMPS)
+OFFSET: buffer index of first sample to read (optional; defaults to 0)[[BR]]
+NUM_SAMPS: number of complex samples to read (optional; defaults to length(OFFSET:rxIQLen-1))[[BR]]
+
+Examples:[[BR]]
+{{{
+%Read full buffer for RFA
+%size(X) will be [rxIQLen, 1]
+X = wl_basebandCmd(node, RFA, 'read_iq');
+
+%Read partial buffer for RFA (samples 1000:4999)
+%size(X) will be [5000, 1]
+X = wl_basebandCmd(node, RFA, 'read_iq', 1000, 5000);
+
+%Read full buffers for RFA and RFB
+%size(X) will be [rxIQLen, 2]
+X = wl_basebandCmd(node, [RFA RFB], 'read_iq');
+}}}
+
+=== {{{read_rssi}}} ===
+Read RSSI samples from the specified buffers. The elements of the buffer selection must be scalers which[[BR]]
+identify a single buffer. To read multiple buffers in one call, pass a vector of individual buffer IDs.[[BR]]
+
+See 'read_iq' for arguments/returns[[BR]]
+
+
+=== {{{agc_state}}} ===
+Read AGC state from the specified buffers. The elements of the buffer selection must be scalers which[[BR]]
+identify a single buffer. To read multiple buffers in one call, pass a vector of individual buffer IDs[[BR]]
+
+
+'''Requires BUFF_SEL:''' Yes (combined BUFF_SEL values not allowed)
+
+'''Arguments:''' none
+
+
+'''Returns:''' agc_state -- column vector per buffer BUFF_SEL
+
+agc_state(1): RF gain chosen by AGC[[BR]]
+agc_state(2): BB gain chosen by AGC[[BR]]
+agc_state(3): RSSI observed by AGC at time of lock[[BR]]
+
+
+=== {{{agc_thresh}}} ===
+Read or write AGC threshold.[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:'''  none or (int32 thresh1), (int32 thresh2), (int32 thresh3)
+
+'''Returns:''' (int32 thresh1), (int32 thresh2), (int32 thresh3) or none
+
+If arguments are specified, this command enters a write mode where[[BR]]
+those arguments are written to the board. If no arguments are specified,[[BR]]
+the current values of agc thresholds are read from the board.[[BR]]
+
+thresh1: receive power (in dBm) under which AGC will not[[BR]]
+attempt to change gains[[BR]]
+default value: -90[[BR]]
+
+thresh2: receive power (in dBm) under which AGC will select[[BR]]
+high RF gain (RF Gain 3)[[BR]]
+default value: -53[[BR]]
+
+thresh3: receive power (in dBm) under which AGC will select[[BR]]
+medium RF gain (RF Gain 2). Above this receive power[[BR]]
+the AGC will select low RF gain (RF Gain 1)[[BR]]
+default value: -43[[BR]]
+
+Default known-good values for this threshold are derived from[[BR]]
+the MAX2829 datasheet (bottom, middle plot on page 16).[[BR]]
+These default values are (-90,-53,-43)dBm. There is no reason[[BR]]
+to call this command unless changing from these defaults is desired.[[BR]]
+
+
+=== {{{agc_target}}} ===
+Set the AGC target[[BR]]
+
+
+'''Requires BUFF_SEL:''' No. Values apply to all RF paths
+
+'''Arguments:''' (int32 target)
+target: target receive power (in dBm)[[BR]]
+default value: -10[[BR]]
+
+'''Returns:''' none
+
+This command is the best way to tweak AGC behavior[[BR]]
+to apply more or less gain. For example, a target of[[BR]]
+-5dBm will apply more gain thatn a target of -10dBm,
+so the waveform will be larger at the inputs of the I[[BR]]
+and Q ADCs.[[BR]]
+
+
+=== {{{agc_noise_est}}} ===
+Set the AGC noise estimate[[BR]]
+
+
+'''Requires BUFF_SEL:''' No. Values apply to all RF paths
+
+'''Arguments:''' (int32 noise_estimate)
+noise_estimate: rx noise power (in dBm)[[BR]]
+default value: -95[[BR]]
+
+'''Returns:''' none
+
+
+=== {{{agc_dco}}} ===
+Enable/disable DC offset correction[[BR]]
+
+
+'''Requires BUFF_SEL:''' No
+
+'''Arguments:''' (boolean DCO)
+DCO:[[BR]]
+true enables DC offset correction[[BR]]
+false disable DC offset correction[[BR]]
+
+'''Returns:''' none
+
+
+=== {{{agc_trig_delay}}} ===
+Sets the AGC trigger delay. The argument specifies a[[BR]]
+delay (in number of cycles) that the AGC should wait[[BR]]
+before beginning its processing after the node[[BR]]
+receives a trigger.[[BR]]
+
+
+'''Requires BUFF_SEL:''' No. Values apply to all RF paths
+
+'''Arguments:''' (uint16 trigger_delay)
+trigger_delay: # if cycles of delay after trigger[[BR]]
+valid range: ![0,511][[BR]]
+
+'''Returns:''' none
+
+
+=== {{{agc_reset}}} ===
+Resets the AGC to its default state[[BR]]
+
+
+'''Requires BUFF_SEL:''' No. Values apply to all RF paths
+
+'''Arguments:''' none
+
+'''Returns:''' none
+
+
+=== {{{agc_done_addr}}} ===
+Sample index where AGC finished[[BR]]
+
+
+'''Requires BUFF_SEL:''' No. Values apply to all RF paths
+
+'''Arguments:''' 
+
+'''Returns:''' (uint32) sample_index