diff --git a/libopenfpga/libpcf/src/base/io_pin_table.h b/libopenfpga/libpcf/src/base/io_pin_table.h
new file mode 100644
index 000000000..50ed3ecce
--- /dev/null
+++ b/libopenfpga/libpcf/src/base/io_pin_table.h
@@ -0,0 +1,101 @@
+#ifndef IO_PIN_TABLE_H
+#define IO_PIN_TABLE_H
+
+/********************************************************************
+ * This file include the declaration of pin constraints
+ *******************************************************************/
+#include <string>
+#include <map>
+#include <array>
+
+/* Headers from vtrutil library */
+#include "vtr_vector.h"
+#include "vtr_geometry.h"
+
+/* Headers from openfpgautil library */
+#include "openfpga_port.h"
+
+#include "io_pin_table_fwd.h"
+
+/* begin namespace openfpga */
+namespace openfpga {
+
+/********************************************************************
+ * A data structure to describe the I/O pin table for FPGA fabrics
+ * This data structure may include a number of I/O pins
+ * each of which contains the following information
+ * - side: the side which this I/O locates on FPGA perimeter
+ * - external_pin_name: the name of the external I/O pin (typically on a packaged chip), which is exposed to end-users
+ * - internal_pin_name: the name of the internal I/O pin (typically inside the chip but on an FPGA fabric), which is defined in FPGA netlists
+ * - direction: the direction of the internal pin, can be input, output or inout 
+ *
+ * The following figure illustrates the relationship between external and internal pins.
+ *                    FPGA Chip
+ *                  +----------------------------------------
+ *                  |                  FPGA fabric
+ *                  |                +----------------------
+ *                  |    +----- +    |
+ *  CHIP_IO_TOP --->|--->| I/O  |--->| FPGA_IN[0]
+ * (External pin)   |    | Ctrl |    | (internal pin as input)
+ *                  |    |      |<---| FPGA_OUT[1]
+ *                  |    +------+    | (internal pin as output) 
+ *
+ * Typical usage:
+ * --------------
+ *   // Create an object
+ *   IoPinTable io_pin_table;
+ *   // Add a pin
+ *   openfpga::BasicPort ext_pin_info("CHIP_IO_TOP", 1);
+ *   openfpga::BasicPort int_pin_info("FPGA_IN", 1, 1);
+ *   IoPinTableId pin_id = io_pin_table.create_io_pin(int_pin_info, ext_pin_info, TOP, INPUT);
+ *
+ *******************************************************************/
+class IoPinTable {
+  public: /* Types */
+    typedef vtr::vector<IoPinTableId, IoPinTableId>::const_iterator io_pin_table_iterator;
+    /* Create range */
+    typedef vtr::Range<io_pin_table_iterator> io_pin_table_range;
+    /* Logic value */
+    enum e_io_direction {
+      INPUT,
+      OUTPUT,
+      NUM_IO_DIRECTIONS
+    };
+  public:  /* Constructors */
+    IoPinTables();
+  public: /* Accessors: aggregates */
+    /* Walk through the internal pins. We do not walk through external pins because they are not unique in the table. 
+     * An external pin may be accessible by two internal pins
+     */
+    io_pin_table_range internal_pins() const;
+  public: /* Public Accessors: Basic data query */
+    /* Get the internal pin */
+    openfpga::BasicPort internal_pin(const IoPinTableId& pin_id) const;
+
+    /* Check if there are any pins */
+    bool empty() const;
+
+  public: /* Public Mutators */
+    /* Reserve to be memory efficent */
+    void reserve_pins(const size_t& num_pins);
+
+    /* Add a pin constraint to storage */
+    IoPinTableId create_pin(const openfpga::BasicPort& pin);
+
+  public: /* Public invalidators/validators */
+    /* Show if the pin id is a valid for data queries */
+    bool valid_pin_id(const IoPinTableId& pin_id) const;
+  private: /* Internal data */
+    /* Unique ids for each design constraint */
+    vtr::vector<IoPinTableId, IoPinTableId> pin_ids_;
+
+    /* Pin information*/
+    vtr::vector<IoPinTableId, BasicPort> internal_pins_;
+    vtr::vector<IoPinTableId, BasicPort> external_pins_;
+    vtr::vector<IoPinTableId, e_side> pin_sides_;
+    vtr::vector<IoPinTableId, e_io_direction> pin_drections_;
+};
+
+} /* end namespace openfpga */
+
+#endif
diff --git a/libopenfpga/libpcf/src/base/io_pin_table_fwd.h b/libopenfpga/libpcf/src/base/io_pin_table_fwd.h
new file mode 100644
index 000000000..3b8c8e518
--- /dev/null
+++ b/libopenfpga/libpcf/src/base/io_pin_table_fwd.h
@@ -0,0 +1,22 @@
+/************************************************************************
+ * A header file for IoPinTable class, including critical data declaration
+ * Please include this file only for using any IoPinTable data structure
+ * Refer to IoPinTable.h for more details 
+ ***********************************************************************/
+
+/************************************************************************
+ * Create strong id for IoPinTable to avoid illegal type casting 
+ ***********************************************************************/
+#ifndef IO_PIN_TABLE_FWD_H
+#define IO_PIN_TABLE_FWD_H
+
+#include "vtr_strong_id.h"
+
+struct io_pin_table_id_tag;
+
+typedef vtr::StrongId<io_pin_table_id_tag> IoPinTableId;
+
+/* Short declaration of class */
+class IoPinTable;
+
+#endif