diff --git a/build/scripts/Targets/TargetDescriptionFiles/AVR8/Avr8TargetDescriptionFile.php b/build/scripts/Targets/TargetDescriptionFiles/AVR8/Avr8TargetDescriptionFile.php
index f9efc506..fcdf2195 100644
--- a/build/scripts/Targets/TargetDescriptionFiles/AVR8/Avr8TargetDescriptionFile.php
+++ b/build/scripts/Targets/TargetDescriptionFiles/AVR8/Avr8TargetDescriptionFile.php
@@ -483,19 +483,24 @@ class Avr8TargetDescriptionFile extends TargetDescriptionFile
         return $output;
     }
 
+    public function getFuseTargetPeripheral(): ?TargetPeripheral
+    {
+        return $this->getTargetPeripheral('fuse');
+    }
+
+    public function getFuseTargetRegisterGroup(): ?TargetRegisterGroup
+    {
+        return $this->getFuseTargetPeripheral()?->getRegisterGroup("fuse");
+    }
+
     public function getFuseBitsDescriptor(string $fuseBitFieldKey): ?FuseBitsDescriptor
     {
-        $peripheral = $this->getTargetPeripheral('fuse') ?? $this->getTargetPeripheral('nvm');
-        if ($peripheral instanceof TargetPeripheral) {
-            $fuseRegisterGroup = $peripheral->getRegisterGroup('fuse')
-                ?? $peripheral->getRegisterGroup('nvm_fuses');
-
-            if ($fuseRegisterGroup instanceof TargetRegisterGroup) {
-                foreach ($fuseRegisterGroup->registers as $fuseRegister) {
-                    foreach ($fuseRegister->bitFields as $bitField) {
-                        if ($bitField->key === $fuseBitFieldKey) {
-                            return new FuseBitsDescriptor($fuseRegister->name);
-                        }
+        $fuseRegisterGroup = $this->getFuseTargetRegisterGroup();
+        if ($fuseRegisterGroup instanceof TargetRegisterGroup) {
+            foreach ($fuseRegisterGroup->registers as $fuseRegister) {
+                foreach ($fuseRegister->bitFields as $bitField) {
+                    if ($bitField->key === $fuseBitFieldKey) {
+                        return new FuseBitsDescriptor($fuseRegister->name);
                     }
                 }
             }
diff --git a/build/scripts/Targets/TargetDescriptionFiles/AVR8/Services/ValidationService.php b/build/scripts/Targets/TargetDescriptionFiles/AVR8/Services/ValidationService.php
index 14ff488f..ba35fcab 100644
--- a/build/scripts/Targets/TargetDescriptionFiles/AVR8/Services/ValidationService.php
+++ b/build/scripts/Targets/TargetDescriptionFiles/AVR8/Services/ValidationService.php
@@ -93,6 +93,13 @@ class ValidationService extends \Targets\TargetDescriptionFiles\Services\Validat
             $failures[] = 'Missing stack pointer register(s) in CPU peripheral';
         }
 
+        // SPL and SPH registers should 1 byte in size
+        foreach ($spRegisters as $register) {
+            if (($register->key === 'spl' || $register->key === 'sph') && $register->size !== 1) {
+                $failures[] = 'Invalid SP register (' . $register->key . ') size - should be 1 byte';
+            }
+        }
+
         /*
          * GDB allows for a maximum SP size of 2 bytes. We enforce this here.
          *
@@ -104,8 +111,29 @@ class ValidationService extends \Targets\TargetDescriptionFiles\Services\Validat
         }
 
         // The target's status register must reside in the CPU peripheral
-        if ($tdf->getTargetRegister("cpu", "cpu", "sreg") === null) {
+        if (($sreg = $tdf->getTargetRegister("cpu", "cpu", "sreg")) === null) {
             $failures[] = 'Missing status (SREG) register in CPU peripheral';
+
+        } elseif ($sreg->size !== 1) {
+            // The SREG should always be 1 byte in size
+            $failures[] = 'Unexpected SREG register size - expected 1 byte, actual size: ' . $sreg->size . ' bytes';
+        }
+
+        if ($tdf->getFuseTargetPeripheral() === null) {
+            $failures[] = 'Missing fuse peripheral';
+        }
+
+        $fuseRegisterGroup = $tdf->getFuseTargetRegisterGroup();
+        if ($fuseRegisterGroup instanceof TargetRegisterGroup) {
+            // All fuse registers should be 1 byte in size
+            foreach ($tdf->getFuseTargetRegisterGroup()->registers as $fuseRegister) {
+                if ($fuseRegister->size != 1) {
+                    $failures[] = 'Fuse register ("' . $fuseRegister->key . '") is not 1 byte in size.';
+                }
+            }
+
+        } else {
+            $failures[] = 'Missing fuse register group (in fuse peripheral)';
         }
 
         if (in_array(AvrPhysicalInterface::DEBUG_WIRE, $debugPhysicalInterfaces)) {
diff --git a/build/scripts/Targets/TargetDescriptionFiles/Services/ValidationService.php b/build/scripts/Targets/TargetDescriptionFiles/Services/ValidationService.php
index b1e61a82..c4b90de1 100644
--- a/build/scripts/Targets/TargetDescriptionFiles/Services/ValidationService.php
+++ b/build/scripts/Targets/TargetDescriptionFiles/Services/ValidationService.php
@@ -606,6 +606,11 @@ class ValidationService
             $failures[] = 'Invalid size (' . $register->size . ')';
         }
 
+        if ($register->size > 8) {
+            // We only support a maximum of 64-bit width for registers, for now
+            $failures[] = 'Width exceeds 64-bit';
+        }
+
         $processedBitFieldKeys = [];
         foreach ($register->bitFields as $bitField) {
             $failures = array_merge($failures, $this->validateBitField($bitField));