diff --git a/common/archcheck.cc b/common/archcheck.cc
index 3c4c3133..1c5d57a0 100644
--- a/common/archcheck.cc
+++ b/common/archcheck.cc
@@ -51,6 +51,16 @@ void archcheck_names(const Context *ctx)
             log_error("wire != wire2, name = %s\n", name.c_str(ctx));
         }
     }
+
+    log_info("Checking partition names..\n");
+    for(PartitionId partition : ctx->getPartitions()) {
+        IdString name = ctx->getPartitionName(partition);
+        PartitionId partition2 = ctx->getPartitionByName(name);
+        if (partition != partition2) {
+            log_error("partition != partition2, name = %s\n", name.c_str(ctx));
+        }
+    }
+
 #ifndef ARCH_ECP5
     log_info("Checking pip names..\n");
     for (PipId pip : ctx->getPips()) {
@@ -187,6 +197,59 @@ void archcheck_conn(const Context *ctx)
     }
 }
 
+void archcheck_partitions(const Context *ctx)
+{
+    log_info("Checking partition data.\n");
+
+    // Partitions should be subsets of BELs that form an exact cover.
+    // In particular that means cell types in a partition should only be
+    // placable in that partition.
+    for(PartitionId partition : ctx->getPartitions()) {
+
+        // Find out which cell types are in this partition.
+        std::unordered_set<IdString> cell_types_in_partition;
+        for(IdString cell_type : ctx->getCellTypes()) {
+            if(ctx->getPartitionForCellType(cell_type) == partition) {
+                cell_types_in_partition.insert(cell_type);
+            }
+        }
+
+        // Make sure that all cell types in this partition have at least one
+        // BelId they can be placed at.
+        std::unordered_set<IdString> cell_types_unused;
+
+        std::unordered_set<BelId> bels_in_partition;
+        for(BelId bel : ctx->getBelsForPartition(partition)) {
+            PartitionId partition2 = ctx->getPartitionForBel(bel);
+            log_assert(partition == partition2);
+
+            bels_in_partition.insert(bel);
+
+            // Check to see if a cell type not in this partition can be
+            // placed at a BEL in this partition.
+            for(IdString cell_type : ctx->getCellTypes()) {
+                if(ctx->getPartitionForCellType(cell_type) == partition) {
+                    if(ctx->isValidBelForCellType(cell_type, bel)) {
+                        cell_types_unused.erase(cell_type);
+                    }
+                } else {
+                    log_assert(!ctx->isValidBelForCellType(cell_type, bel));
+                }
+            }
+        }
+
+        // Verify that any BEL not in this partition reports a different
+        // partition.
+        for(BelId bel : ctx->getBels()) {
+            if(ctx->getPartitionForBel(bel) != partition) {
+                log_assert(bels_in_partition.count(bel) == 0);
+            }
+        }
+
+        log_assert(cell_types_unused.empty());
+    }
+}
+
 } // namespace
 
 NEXTPNR_NAMESPACE_BEGIN
@@ -199,6 +262,7 @@ void Context::archcheck() const
     archcheck_names(this);
     archcheck_locs(this);
     archcheck_conn(this);
+    archcheck_partitions(this);
 }
 
 NEXTPNR_NAMESPACE_END
diff --git a/docs/archapi.md b/docs/archapi.md
index 3a0efcce..53132bd9 100644
--- a/docs/archapi.md
+++ b/docs/archapi.md
@@ -88,6 +88,14 @@ Get Z dimension for the specified tile for bels. All bels with at specified X an
 
 Get Z dimension for the specified tile for pips. All pips with at specified X and Y coordinates must have a Z coordinate in the range `0 .. getTileDimZ(X,Y)-1` (inclusive).
 
+Cell Methods
+-----------
+
+### const\_range\<IdString\> getCellTypes() const
+
+Get list of cell types that this architecture accepts.
+
+
 Bel Methods
 -----------
 
@@ -478,8 +486,8 @@ information for all edges. `index` must be in [0, clockInfoCount), behaviour is
 Partition Methods
 -----------------
 
-Partitions are used by analytic placement to seperate types of BELs during
-placement.  Typical partitions are:
+Partitions are subsets of BelIds and cell types used by analytic placement to 
+seperate types of BELs during placement.  Typical partitions are:
  - All LUT BELs
  - All FF BELs
  - All multipliers BELs
@@ -487,7 +495,8 @@ placement.  Typical partitions are:
  - etc.
 
 The general rule here is to include all BELs that are roughly interchangable
-during placement.
+during placement.  Partitions should form an exact cover over all BelIds and
+cell types.
 
 ### const\_range\<PartitionId\> getPartitions() const
 
@@ -497,8 +506,16 @@ Return a list of all partitions on the device.
 
 Return the name of the partition.
 
+### PartitionId getPartitionByName(IdString partition\_name) const
+
+Return the partition for the specified partition name.
+
 ### PartitionId getPartitionForBel(BelId bel) const
 
+Returns the partition for a particular BEL.
+
+### PartitionId getPartitionForCell(IdString cell\_type) const
+
 Returns the partition for a particular cell type.
 
 ### const\_range\<BelId\> getBelsForPartition(PartitionId partition) const
diff --git a/generic/arch.h b/generic/arch.h
index abe7ff7d..b1af5175 100644
--- a/generic/arch.h
+++ b/generic/arch.h
@@ -271,6 +271,34 @@ struct Arch : BaseCtx
     bool place();
     bool route();
 
+    std::vector<IdString> getCellTypes() const {
+        return {};
+    }
+
+    std::vector<PartitionId> getPartitions() const {
+        return {};
+    }
+
+    IdString getPartitionName(PartitionId partition) const {
+        return partition;
+    }
+
+    PartitionId getPartitionByName(IdString partition) const {
+        return partition;
+    }
+
+    PartitionId getPartitionForBel(BelId bel) const {
+        return getBelType(bel);
+    }
+
+    PartitionId getPartitionForCellType(IdString cell_type) const {
+        return cell_type;
+    }
+
+    std::vector<BelId> getBelsForPartition(PartitionId partition) const {
+        return {};
+    }
+
     const std::vector<GraphicElement> &getDecalGraphics(DecalId decal) const;
     DecalXY getBelDecal(BelId bel) const;
     DecalXY getWireDecal(WireId wire) const;
diff --git a/generic/archdefs.h b/generic/archdefs.h
index 978c9c9b..cb78249a 100644
--- a/generic/archdefs.h
+++ b/generic/archdefs.h
@@ -51,6 +51,7 @@ typedef IdString WireId;
 typedef IdString PipId;
 typedef IdString GroupId;
 typedef IdString DecalId;
+typedef IdString PartitionId;
 
 struct ArchNetInfo
 {