Fix transfer length checks

Signed-off-by: Alex Forencich <alex@alexforencich.com>

cocotbext/axi/axil_master.py

@@ -159,6 +159,9 @@ class AxiLiteMasterWrite(Region, Reset):
         if isinstance(data, int):
             raise ValueError("Expected bytes or bytearray for data")
 
+        if address+len(data) > 2**self.address_width:
+            raise ValueError("Requested transfer overruns end of address space")
+
         if not self.awprot_present and prot != AxiProt.NONSECURE:
             raise ValueError("awprot sideband signal value specified, but signal is not connected")
 
@@ -182,7 +185,7 @@ class AxiLiteMasterWrite(Region, Reset):
         if isinstance(data, int):
             raise ValueError("Expected bytes or bytearray for data")
 
-        if address+len(data) >= 2**self.address_width:
+        if address+len(data) > 2**self.address_width:
             raise ValueError("Requested transfer overruns end of address space")
 
         if not self.awprot_present and prot != AxiProt.NONSECURE:
@@ -404,6 +407,12 @@ class AxiLiteMasterRead(Region, Reset):
         if address < 0 or address >= 2**self.address_width:
             raise ValueError("Address out of range")
 
+        if length < 0:
+            raise ValueError("Read length must be positive")
+
+        if address+length > 2**self.address_width:
+            raise ValueError("Requested transfer overruns end of address space")
+
         if not self.arprot_present and prot != AxiProt.NONSECURE:
             raise ValueError("arprot sideband signal value specified, but signal is not connected")
 
@@ -425,7 +434,7 @@ class AxiLiteMasterRead(Region, Reset):
         if length < 0:
             raise ValueError("Read length must be positive")
 
-        if address+length >= 2**self.address_width:
+        if address+length > 2**self.address_width:
             raise ValueError("Requested transfer overruns end of address space")
 
         if not self.arprot_present and prot != AxiProt.NONSECURE: