diff --git a/spec/chip.typ b/spec/chip.typ
index c694db90a..ad7e1a7eb 100644
--- a/spec/chip.typ
+++ b/spec/chip.typ
@@ -1,4 +1,4 @@
-#import "expr.typ": expr_to_code, expr_to_math
+#import "expr.typ": expr_to_code, expr_to_math, type_to_code
 
 /// Computes the total number of variables in a `chip`
 #let total_nr_variables(chip) = {
@@ -13,7 +13,14 @@
   .filter(pair => pair.at(0) in config.variables.categories.instantiated)
   .map(pair => pair.at(1))
   .flatten()
-  .map(var => config.variables.types.filter(type => type.label == var.type).at(0).subtypes.len())
+  .map(var => {
+    let (label, factor) = if type(var.type) == array {
+      (var.type.at(0), var.type.at(1))
+    } else {
+      (var.type, 1)
+    }
+    config.variables.types.filter(type => type.label == label).first().subtypes.len() * factor
+  })
   .sum()
 }
 
@@ -30,7 +37,7 @@
     ..for (cat, vars) in chip.variables.pairs() {
       ([#emph(cat)], [], [], table.hline(stroke: .6pt))
       for var in vars {
-        ([#raw(var.name)], [#raw(var.type)], [#eval(var.desc, mode: "markup")])
+        ([#raw(var.name)], [#type_to_code(var.type)], [#eval(var.desc, mode: "markup")])
         for (i, poly) in var.at("polys", default: ()).enumerate() {
           (if i == 0 { emph[def] }, [], expr_to_math(("=", ("idx", var.name, i), poly)))
         }
diff --git a/spec/expr.typ b/spec/expr.typ
index df1ddb2e6..ab5be4704 100644
--- a/spec/expr.typ
+++ b/spec/expr.typ
@@ -117,3 +117,24 @@
   var: v => if v.len() == 1 { $#v$ } else { $#raw(v)$ },
   num: n => math.equation[#n],
 )
+
+// Check that a type expression is structurally valid, without validating against a set of known base types
+#let check_array_type(typ) = {
+  assert(type(typ.at(0)) == str, message: "Array types need to have a regular type as base")
+  assert(type(typ.at(1)) == int, message: "Array types need to have a constant dimension")
+}
+
+// Render a type to code
+#let type_to_code(typ) = {
+  if type(typ) == array {
+    check_array_type(typ)
+    return raw(typ.at(0) + "[" + str(typ.at(1)) + "]")
+  } else if type(typ) == string {
+    return raw(typ)
+  } else {
+    assert(false, message: "Unknown format for type: " + repr(typ))
+  }
+}
+
+// Render a type to math
+#let type_to_math(typ) = render_type_to_code(typ) // The code version looks reasonable enough in math too
diff --git a/spec/src.typ b/spec/src.typ
index f791bc1ca..75a81a5f9 100644
--- a/spec/src.typ
+++ b/spec/src.typ
@@ -38,12 +38,16 @@
     assert(category in config.variables.categories.all)
   }
 
+  let all_labels = config.variables.types.map(type => type.label);
   for var in chip.variables.values().flatten() {
+    let type_label = if type(var.type) == array {
+      var.type.at(0)
+    } else {
+      var.type
+    }
+
     // Check that all variable types are valid
-    assert(
-      var.type in config.variables.types.map(type => type.label),
-      message: "found invalid var type:" + var.type,
-    )
+    assert(type_label in all_labels, message: "found invalid var type:" + repr(var.type))
   }
 }
 
diff --git a/spec/src/config.toml b/spec/src/config.toml
index 1977b9155..29c0b9d83 100644
--- a/spec/src/config.toml
+++ b/spec/src/config.toml
@@ -81,33 +81,6 @@ desc = """\
        The `Word` is the least significant digit.
        """
 
-# TODO: Having to define these manually will get tedious
-[[variables.types]]
-label = "Bit[3]"
-subtypes = ["Bit", "Bit", "Bit"]
-desc = "Three bits"
-
-[[variables.types]]
-label = "Byte[2]"
-subtypes = ["Byte", "Byte"]
-desc = "Two bytes"
-
-[[variables.types]]
-label = "Byte[8]"
-subtypes = ["Byte", "Byte", "Byte", "Byte", "Byte", "Byte", "Byte", "Byte"]
-desc = "Eight bytes"
-
-[[variables.types]]
-label = "Half[3]"
-subtypes = ["Half", "Half", "Half"]
-desc = "Three halfwords"
-
-[[variables.types]]
-label = "Half[8]"
-subtypes = ["Half", "Half", "Half", "Half", "Half", "Half", "Half", "Half"]
-desc = "Eight halfwords"
-
-
 [variables.categories]
 all = ["input", "output", "auxiliary", "virtual", "multiplicity"]
 instantiated = ["input", "output", "auxiliary", "multiplicity"]