Selective loading of configuration data into configuration memory cells

1. A programmable logic device comprising:

a non-volatile memory adapted to store a first bit, a second bit, and a plurality of configuration data;

a plurality of configuration memory cells adapted to receive configuration data transferred from the non-volatile memory; and

control logic adapted to determine based on the logic states of the first and second bits stored in the non-volatile memory and prior to any transfer of the configuration data whether to transfer the configuration data from the non-volatile memory to the configuration memory cells.

2. The programmable logic device of claim 1 , wherein the control logic is further adapted to transfer the configuration data if the first and second bits are of opposite logic states and to not transfer the configuration data if the first and second bits are of the same logic state.

3. The programmable logic device of claim 1 , wherein the first bit is a validation bit and the second bit is a stop bit.

4. The programmable logic device of claim 1 , wherein the first bit is adjacent to the second bit in the non-volatile memory.

5. The programmable logic device of claim 1 , further comprising a data port adapted to receive instructions to program the first and second bits.

6. The programmable logic device of claim 1 , wherein the control logic comprises a register adapted to receive the first bit and the second bit from the non-volatile memory.

7. The programmable logic device of claim 1 , further comprising a plurality of sense amplifiers adapted to provide the first bit and the second bit to the control logic.

8. The programmable logic device of claim 1 , wherein the configuration memory cells are volatile SRAM memory cells.

9. The programmable logic device of claim 1 , wherein the non-volatile memory is a flash memory.

10. A programmable logic device comprising:

a non-volatile memory adapted to store a first bit, a second bit adjacent to the first bit, and a plurality of configuration data;

a plurality of configuration memory cells adapted to receive configuration data transferred from the non-volatile memory; and

control logic adapted to compare the logic state of the first bit to the logic state of the second bit to determine whether to transfer the configuration data to the configuration memory cells.

11. The programmable logic device of claim 10 , wherein the control logic is further adapted to compare the logic state of the first bit to the logic state of the second bit prior to transfer of the configuration data from the non-volatile memory to the configuration memory cells.

12. The programmable logic device of claim 10 , wherein the control logic is further adapted to transfer the configuration data from the non-volatile memory to the configuration memory cells only if the first and second bits are of opposite logic states.

13. The method of claim 10 , wherein the non-volatile memory is a flash memory.

14. A method of controlling a programmable logic device, the method comprising:

reading a first bit and a second bit of a non-volatile memory within the device, wherein the non-volatile memory is adapted to store the first bit, the second bit, and a plurality of configuration data; and

based on the logic states of the first and second bits stored in the non-volatile memory and prior to any transfer of the configuration data, determining whether to transfer the configuration data from the non-volatile memory to configuration memory cells within the device.

15. The method of claim 14 including transferring the configuration data if the first and second bits are of opposite logic states and not transferring the configuration data if the first and second bits are of the same logic state.

16. The method of claim 14 , wherein the method is performed by control logic of the programmable logic device.

17. The method of claim 14 , wherein the method is performed in response to a powering up of the programmable logic device.

18. The method of claim 14 , wherein the first bit is adjacent to the second bit in the non-volatile memory.

19. The method of claim 14 , wherein the configuration memory cells are volatile memory cells.

20. The method of claim 14 , wherein the first bit is a validation bit and the second bit is a stop bit.