add veriloggen axistream elias python code

samples/axis/elias.py

@@ -0,0 +1,123 @@
+from __future__ import absolute_import
+from __future__ import print_function
+import sys
+import os
+import math
+
+# the next line can be removed after installation
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))))
+
+from veriloggen import *
+import veriloggen.thread as vthread
+import veriloggen.types.axi as axi
+
+
+def mkElias(iw=32, ow=8):
+    maxlen = 2*int(math.log(iw, 2))
+    fifodep = 10
+    m = Module('Elias')
+    m.Localparam('IW', iw)
+    m.Localparam('MAXLEN', maxlen) 
+
+
+    clk = m.Input('CLK')
+    rst = m.Input('RST')
+    din = m.Reg('din',iw)
+    bitlen = m.Reg('bitlen',maxlen)
+    dout = m.Reg('dout',iw)
+
+    curval = m.Reg('curval',2*iw)
+    curlen = m.Reg('curlen',maxlen)
+    nextval = m.Reg('nextval',2*iw)
+    nextlen = m.Reg('nextlen',maxlen)
+
+    m.EmbeddedCode("""
+    integer i;
+    reg [MAXLEN-1:0] cnt;
+    reg [IW-1:0] data;
+    always @* begin
+		for (i = 0; i < IW; i = i+1)
+			data[i] = din[(IW-i-1)];
+		data = (data-1) & ~data;
+        cnt = 0;
+		for (i = 0; i < IW; i = i+1)
+			cnt = cnt + data[i];
+        bitlen = IW - cnt;
+        dout = din;
+        bitlen = bitlen + bitlen - 1;
+        
+	end
+    """) 
+
+
+
+
+    axi_in = vthread.AXIStreamInFifo(m, 'axi_in', clk, rst, iw,
+                                     with_last=True)
+
+    axi_out = vthread.AXIStreamOutFifo(m, 'axi_out', clk, rst, ow,
+                                       with_last=True)
+
+    fifo_addrwidth = 8
+    fifo_in = vthread.FIFO(m, 'fifo_in', clk, rst, iw, fifodep)
+    fifo_out = vthread.FIFO(m, 'fifo_out', clk, rst, ow, fifodep)
+    fifo_val = vthread.FIFO(m, 'fifo_val', clk, rst, 2*iw, fifodep)
+    fifo_len = vthread.FIFO(m, 'fifo_len', clk, rst, maxlen, fifodep )
+
+
+    def recv():
+        while 1:
+           data, last = axi_in.read()
+           fifo_in.enq(data)
+
+
+    def clen():
+        while 1:
+            din.value = fifo_in.deq()
+            vthread.set_parallel()
+            fifo_val.enq(dout)
+            fifo_len.enq(bitlen)
+            vthread.unset_parallel()
+
+    def comb():
+        curlen.value = fifo_len.deq()
+        curval.value = fifo_val.deq() << (2*iw - curlen)
+        while 1:
+            while curlen < ow:
+                nextval.value = fifo_val.deq()
+                nextlen.value = fifo_len.deq()
+                curval.value = curval + (nextval<<(2*iw - curlen - nextlen))
+                curlen.value = curlen + nextlen
+            fifo_out.enq(curval[2*iw-ow:2*iw])
+            curval.value = curval << ow
+            curlen.value = curlen - ow
+
+
+    def send():
+        while 1:
+           data = fifo_out.deq()
+           axi_out.write(data)
+
+    th_recv = vthread.Thread(m, 'recv', clk, rst, recv)
+    th_clen = vthread.Thread(m, 'clen', clk, rst, clen)
+    th_comb = vthread.Thread(m, 'comb', clk, rst, comb)
+    th_send = vthread.Thread(m, 'send', clk, rst, send)
+    fsm = th_recv.start()
+    fsm = th_clen.start()
+    fsm = th_comb.start()
+    fsm = th_send.start()
+    return m
+
+
+
+
+def run(filename='tmp.v', simtype='iverilog', outputfile=None):
+    test = mkElias()
+    code = test.to_verilog(filename)
+    return code
+
+
+if __name__ == '__main__':
+    rslt = run(filename='tmp.v')
+    print(rslt)