added random testing

2 files changed, 91 insertions, 2 deletions

diff --git a/hdl/config.py b/hdl/config.py
index 4761c0a..989a090 100644
--- a/hdl/config.py
+++ b/hdl/config.py
@@ -5,4 +5,6 @@ ROOT_DIR = os.path.dirname(os.path.abspath(__file__))
 HDL_PATH = os.path.join(ROOT_DIR, 'hdl')
 VERILOG_DIR = os.path.join(ROOT_DIR, 'gen_verilog')
 CXXRTL_DIR = os.path.join(ROOT_DIR, 'gen_cxxrtl')
-VCD_DIR = os.path.join(ROOT_DIR, 'gen_vcd')
\ No newline at end of file
+VCD_DIR = os.path.join(ROOT_DIR, 'gen_vcd')
+
+NUM_RAND_TESTS = 250
\ No newline at end of file
diff --git a/hdl/utils.py b/hdl/utils.py
index b496356..a6e8de4 100644
--- a/hdl/utils.py
+++ b/hdl/utils.py
@@ -1,13 +1,21 @@
+# general imports
 import sys
 from inspect import stack   # get name of caller function
 from typing import Callable
+import random
+
+#hdl specific imports
 from amaranth import *
 from amaranth import Elaboratable
 from amaranth.back import verilog, cxxrtl
 from amaranth.sim import Settle, Delay, Simulator
 
+#custom imports 
 from hdl.config import *
 
+# configuration
+random.seed(5498)
+
 
 def cmd(hdl):
     '''
@@ -49,4 +57,83 @@ def step(cycles=1):
         yield Settle()  # settle comb logic before clock
         yield           # clock edge
         yield Settle()  # settle comb logic after clock
-    yield Delay(5e-7)   # used for debugging, change values on neg edge of clock
\ No newline at end of file
+    yield Delay(5e-7)   # used for debugging, change values on neg edge of clock
+
+def eval():
+    yield Settle()
+    yield Delay(1e-6)
+
+# bits can be integer or Signal
+def rand_bits(bits, sus=None, low=None, high=None):
+    '''
+    Takes number of bits or a Signal and returns a random number
+    if low and high are not specified, the range is 0 to 2**bits - 1
+    If low and high are specified the number of bits is ignored
+    sus (Signed UnSigned) can be 's' or 'u' to force signed or unsigned, default is random
+    sus has no effect if low and high are specified
+    '''
+
+    if isinstance(bits, Signal):
+        bits = bits.width
+
+    if (low == high == None):
+        if sus == 's':
+            low = -2**(bits-1)
+            high = 2**(bits-1) - 1
+        elif sus == 'u':
+            low = 0
+            high = 2**bits - 1
+        else:
+            if random.random() < 0.5:
+                low = 0
+                high = 2**bits - 1
+            else:
+                low = -2**(bits-1)
+                high = 2**(bits-1) - 1
+    else:
+        assert low < high, "low must be less than high"
+        assert low != None, "low must be defined if high is defined"
+        assert high != None, "high must be defined if low is defined"
+
+    return random.randint(low, high)
+
+# bits can be integer or Signal
+def rand_bits_extremes(bits, sus=None):
+    '''
+    Takes number of bits or a Signal and returns a random number with the extremes of the range
+    sus (Signed UnSigned) can be 's' or 'u' to force signed or unsigned, default is random
+    '''
+
+    if isinstance(bits, Signal):
+        bits = bits.width
+
+    if sus == 's':
+        low = -2**(bits-1)
+        high = 2**(bits-1) - 1
+    elif sus == 'u':
+        low = 0
+        high = 2**bits - 1
+    else:
+        if random.random() < 0.5:
+            low = 0
+            high = 2**bits - 1
+        else:
+            low = -2**(bits-1)
+            high = 2**(bits-1) - 1
+        
+    choices = [low, high] if low == 0 else [low, 0, high]   # if low is 0, don't include it as a choice
+    return random.choice(choices)
+
+
+def rand_bits_mix(bits, low=None, high=None, sus=None, extrem_prob=0.25):
+    '''
+    Take number of bits or a Signal
+    sus determines if the number is signed or unsigned, or both ('s', 'u', or None)
+    Returns a random number with increased likelihood of extremes
+    If low and high are specified the number of bits is ignored
+    The likelyhood of extremes is determined by extrem_prob, default is 0.25
+    '''
+    if random.random() <= extrem_prob:
+        return rand_bits_extremes(bits, sus=sus)
+    else:
+        return rand_bits(bits, sus=sus, low=low, high=high)