module chan_fifo_reader
- ( reset, tx_clock, tx_strobe, adc_time, samples_format,
+ (reset, tx_clock, tx_strobe, timestamp_clock, samples_format,
fifodata, pkt_waiting, rdreq, skip, tx_q, tx_i,
underrun, tx_empty, debug, rssi, threshhold, rssi_wait) ;
- input wire reset ;
- input wire tx_clock ;
- input wire tx_strobe ; //signal to output tx_i and tx_q
- input wire [31:0] adc_time ; //current time
- input wire [3:0] samples_format ;// not useful at this point
- input wire [31:0] fifodata ; //the data input
- input wire pkt_waiting ; //signal the next packet is ready
- output reg rdreq ; //actually an ack to the current fifodata
- output reg skip ; //finish reading current packet
- output reg [15:0] tx_q ; //top 16 bit output of fifodata
- output reg [15:0] tx_i ; //bottom 16 bit output of fifodata
- output reg underrun ;
- output reg tx_empty ; //cause 0 to be the output
- input wire [31:0] rssi;
- input wire [31:0] threshhold;
- input wire [31:0] rssi_wait;
+ input wire reset ;
+ input wire tx_clock ;
+ input wire tx_strobe ; //signal to output tx_i and tx_q
+ input wire [31:0] timestamp_clock ; //current time
+ input wire [3:0] samples_format ;// not useful at this point
+ input wire [31:0] fifodata ; //the data input
+ input wire pkt_waiting ; //signal the next packet is ready
+ output reg rdreq ; //actually an ack to the current fifodata
+ output reg skip ; //finish reading current packet
+ output reg [15:0] tx_q ; //top 16 bit output of fifodata
+ output reg [15:0] tx_i ; //bottom 16 bit output of fifodata
+ output reg underrun ;
+ output reg tx_empty ; //cause 0 to be the output
+ input wire [31:0] rssi;
+ input wire [31:0] threshhold;
+ input wire [31:0] rssi_wait;
- output wire [14:0] debug;
- assign debug = {reader_state, trash, skip, timestamp[4:0], adc_time[4:0]};
- // Should not be needed if adc clock rate < tx clock rate
- // Used only to debug
- `define JITTER 5
-
- //Samples format
- // 16 bits interleaved complex samples
- `define QI16 4'b0
+ output wire [14:0] debug;
+ assign debug = {7'd0, rdreq, skip, reader_state, pkt_waiting, tx_strobe, tx_clock};
+
+ //Samples format
+ // 16 bits interleaved complex samples
+ `define QI16 4'b0
- // States
- parameter IDLE = 3'd0;
- parameter HEADER = 3'd1;
- parameter TIMESTAMP = 3'd2;
- parameter WAIT = 3'd3;
- parameter WAITSTROBE = 3'd4;
- parameter SEND = 3'd5;
+ // States
+ parameter IDLE = 3'd0;
+ parameter HEADER = 3'd1;
+ parameter TIMESTAMP = 3'd2;
+ parameter WAIT = 3'd3;
+ parameter WAITSTROBE = 3'd4;
+ parameter SEND = 3'd5;
- // Header format
- `define PAYLOAD 8:2
- `define ENDOFBURST 27
- `define STARTOFBURST 28
- `define RSSI_FLAG 26
+ // Header format
+ `define PAYLOAD 8:2
+ `define ENDOFBURST 27
+ `define STARTOFBURST 28
+ `define RSSI_FLAG 26
- /* State registers */
- reg [2:0] reader_state;
- /* Local registers */
- reg [6:0] payload_len;
- reg [6:0] read_len;
- reg [31:0] timestamp;
- reg burst;
- reg trash;
- reg rssi_flag;
- reg [31:0] time_wait;
+ /* State registers */
+ reg [2:0] reader_state;
+ /* Local registers */
+ reg [6:0] payload_len;
+ reg [6:0] read_len;
+ reg [31:0] timestamp;
+ reg burst;
+ reg trash;
+ reg rssi_flag;
+ reg [31:0] time_wait;
- always @(posedge tx_clock)
- begin
- if (reset)
- begin
- reader_state <= IDLE;
- rdreq <= 0;
- skip <= 0;
- underrun <= 0;
- burst <= 0;
- tx_empty <= 1;
- tx_q <= 0;
- tx_i <= 0;
- trash <= 0;
- rssi_flag <= 0;
- time_wait <= 0;
+ always @(posedge tx_clock)
+ begin
+ if (reset)
+ begin
+ reader_state <= IDLE;
+ rdreq <= 0;
+ skip <= 0;
+ underrun <= 0;
+ burst <= 0;
+ tx_empty <= 1;
+ tx_q <= 0;
+ tx_i <= 0;
+ trash <= 0;
+ rssi_flag <= 0;
+ time_wait <= 0;
end
else
- begin
+ begin
case (reader_state)
- IDLE:
+ IDLE:
begin
- /*
- * reset all the variables and wait for a tx_strobe
- * it is assumed that the ram connected to this fifo_reader
- * is a short hand fifo meaning that the header to the next packet
- * is already available to this fifo_reader when pkt_waiting is on
- */
- skip <=0;
- time_wait <= 0;
- if (pkt_waiting == 1)
- begin
- reader_state <= HEADER;
- rdreq <= 1;
- underrun <= 0;
- end
- if (burst == 1 && pkt_waiting == 0)
- underrun <= 1;
-
- if (tx_strobe == 1)
- tx_empty <= 1 ;
+ /*
+ * reset all the variables and wait for a tx_strobe
+ * it is assumed that the ram connected to this fifo_reader
+ * is a short hand fifo meaning that the header to the next packet
+ * is already available to this fifo_reader when pkt_waiting is on
+ */
+ skip <=0;
+ time_wait <= 0;
+ if (pkt_waiting == 1)
+ begin
+ reader_state <= HEADER;
+ rdreq <= 1;
+ underrun <= 0;
+ end
+ if (burst == 1 && pkt_waiting == 0)
+ underrun <= 1;
+ if (tx_strobe == 1)
+ tx_empty <= 1 ;
end
- /* Process header */
+ /* Process header */
HEADER:
- begin
+ begin
if (tx_strobe == 1)
tx_empty <= 1 ;
else if (fifodata[`ENDOFBURST] == 1)
burst <= 0;
- if (trash == 1 && fifodata[`STARTOFBURST] == 0)
- begin
- skip <= 1;
- reader_state <= IDLE;
- rdreq <= 0;
- end
- else
- begin
- payload_len <= fifodata[`PAYLOAD] ;
- read_len <= 0;
- rdreq <= 1;
- reader_state <= TIMESTAMP;
- end
- end
+ if (trash == 1 && fifodata[`STARTOFBURST] == 0)
+ begin
+ skip <= 1;
+ reader_state <= IDLE;
+ rdreq <= 0;
+ end
+ else
+ begin
+ payload_len <= fifodata[`PAYLOAD] ;
+ read_len <= 0;
+ rdreq <= 1;
+ reader_state <= TIMESTAMP;
+ end
+ end
TIMESTAMP:
- begin
+ begin
timestamp <= fifodata;
reader_state <= WAIT;
if (tx_strobe == 1)
tx_empty <= 1 ;
rdreq <= 0;
- end
+ end
- // Decide if we wait, send or discard samples
+ // Decide if we wait, send or discard samples
WAIT:
- begin
+ begin
if (tx_strobe == 1)
tx_empty <= 1 ;
time_wait <= time_wait + 32'd1;
- // Outdated
- if ((timestamp < adc_time) ||
- (time_wait >= rssi_wait && rssi_wait != 0 && rssi_flag))
+ // Outdated
+ if ((timestamp < timestamp_clock) ||
+ (time_wait >= rssi_wait && rssi_wait != 0 && rssi_flag))
begin
- trash <= 1;
- reader_state <= IDLE;
- skip <= 1;
+ trash <= 1;
+ reader_state <= IDLE;
+ skip <= 1;
end
// Let's send it
- else if ((timestamp <= adc_time + `JITTER
- && timestamp > adc_time)
+ else if (timestamp == timestamp_clock
|| timestamp == 32'hFFFFFFFF)
- begin
- if (rssi <= threshhold || rssi_flag == 0)
- begin
- trash <= 0;
- reader_state <= WAITSTROBE;
- end
- else
- reader_state <= WAIT;
- end
- else
- reader_state <= WAIT;
- // Wait a little bit more
- //else if (timestamp > adc_time + `JITTER)
- // reader_state <= WAIT;
- end
+ begin
+ if (rssi <= threshhold || rssi_flag == 0)
+ begin
+ trash <= 0;
+ reader_state <= WAITSTROBE;
+ end
+ else
+ reader_state <= WAIT;
+ end
+ else
+ reader_state <= WAIT;
+ end
// Wait for the transmit chain to be ready
WAITSTROBE:
- begin
+ begin
// If end of payload...
if (read_len == payload_len)
begin
reader_state <= SEND;
rdreq <= 1;
end
- end
+ end
- // Send the samples to the tx_chain
+ // Send the samples to the tx_chain
SEND:
- begin
+ begin
reader_state <= WAITSTROBE;
read_len <= read_len + 7'd1;
tx_empty <= 0;
tx_q <= fifodata[31:16];
end
endcase
- end
+ end
default:
- begin
- //error handling
+ begin
+ //error handling
reader_state <= IDLE;
- end
+ end
endcase
end
end
projects / debian / gnuradio / blobdiff