101-bram-config: READ/WRITE_WIDTH SRVAL/INIT parity tweaks

Signed-off-by: John McMaster <johndmcmaster@gmail.com>

fuzzers/101-bram-config/Makefile

@@ -1,5 +1,5 @@
 # read/write width is relatively slow to resolve
-N := 2
+N := 4
 SPECIMENS := $(addprefix build/specimen_,$(shell seq -f '%03.0f' $(N)))
 SPECIMENS_OK := $(addsuffix /OK,$(SPECIMENS))
 

fuzzers/101-bram-config/generate.py

@@ -34,8 +34,14 @@ def bus_tags(segmk, ps, site):
     for param, tagname in [('SRVAL_A', 'ZSRVAL_A'), ('SRVAL_B', 'ZSRVAL_B'),
                            ('INIT_A', 'ZINIT_A'), ('INIT_B', 'ZINIT_B')]:
         bitstr = verilog.parse_bitstr(ps[param])
+        ab = param[-1]
+        # Are all bits present?
+        hasparity = ps['READ_WIDTH_' + ab] == 18
         for i in range(18):
-            segmk.add_site_tag(site, '%s[%u]' % (param, i), 1 ^ bitstr[i])
+            # Magic bit positions from experimentation
+            # we could just only solve when parity, but this check documents the fine points a bit better
+            if hasparity or i not in (1, 9):
+                segmk.add_site_tag(site, '%s[%u]' % (param, i), 1 ^ bitstr[i])
 
 
 def rw_width_tags(segmk, ps, site):
@@ -83,8 +89,8 @@ def run():
         site = verilog.unquote(ps['LOC'])
         #print('site', site)
 
-        # isenv_tags(segmk, ps, site)
-        # bus_tags(segmk, ps, site)
+        isenv_tags(segmk, ps, site)
+        bus_tags(segmk, ps, site)
         rw_width_tags(segmk, ps, site)
 
     def bitfilter(frame, bit):

fuzzers/101-bram-config/top.py

@@ -3,6 +3,7 @@ import random
 random.seed(int(os.getenv("SEED"), 16))
 from prjxray import util
 from prjxray import verilog
+from prjxray.verilog import vrandbit, vrandbits
 import sys
 import json
 
@@ -57,21 +58,6 @@ print(
     'module roi(input clk, input [%d:0] din, output [%d:0] dout);' %
     (DIN_N - 1, DOUT_N - 1))
 
-
-def vrandbit():
-    if random.randint(0, 1):
-        return "1'b1"
-    else:
-        return "1'b0"
-
-
-def vrandbits(n):
-    ret = "%u'b" % n
-    for _i in range(n):
-        ret += str(random.randint(0, 1))
-    return ret
-
-
 for loci, (site_type, site) in enumerate(brams):
 
     def place_bram18():
@@ -80,6 +66,11 @@ for loci, (site_type, site) in enumerate(brams):
             'din': 'din[  %d +: 8]' % (8 * loci, ),
             'dout': 'dout[  %d +: 8]' % (8 * loci, ),
         }
+
+        # Datasheet says 72 is legal in some cases, but think its a copy paste error from BRAM36
+        # also 0 and 36 aren't real sizes
+        # Bias choice to 18 as its needed to solve certain bits quickly
+        widths = [1, 2, 4, 9, 18, 18, 18, 18]
         params = {
             'LOC': verilog.quote(site),
             'IS_CLKARDCLK_INVERTED': vrandbit(),
@@ -99,13 +90,12 @@ for loci, (site_type, site) in enumerate(brams):
             "SRVAL_B": vrandbits(18),
             "INIT_A": vrandbits(18),
             "INIT_B": vrandbits(18),
-            # Datasheet says 72 is legal, but think its a copy paste error from BRAM36
-            # also 0 and 36 aren't real sizes
-            "READ_WIDTH_A": random.choice([1, 2, 4, 9, 18]),
-            "READ_WIDTH_B": random.choice([1, 2, 4, 9, 18]),
-            "WRITE_WIDTH_A": random.choice([1, 2, 4, 9, 18]),
-            "WRITE_WIDTH_B": random.choice([1, 2, 4, 9, 18]),
+            "READ_WIDTH_A": random.choice(widths),
+            "READ_WIDTH_B": random.choice(widths),
+            "WRITE_WIDTH_A": random.choice(widths),
+            "WRITE_WIDTH_B": random.choice(widths),
         }
+
         return ('my_RAMB18E1', ports, params)
 
     def place_bram36():

prjxray/verilog.py

@@ -1,4 +1,5 @@
 import sys
+import random
 
 
 def top_harness(DIN_N, DOUT_N, f=sys.stdout):
@@ -76,3 +77,17 @@ def parse_bitstr(s):
     bitstr = postfix[1:]
     assert len(bitstr) == n
     return [int(x) for x in bitstr]
+
+
+def vrandbit():
+    if random.randint(0, 1):
+        return "1'b1"
+    else:
+        return "1'b0"
+
+
+def vrandbits(n):
+    ret = "%u'b" % n
+    for _i in range(n):
+        ret += str(random.randint(0, 1))
+    return ret