Combined EEPROM/flash non-volatile memory circuit
A non-volatile memory circuit includes memory rows and supporting circuits coupled to the memory rows, where at least one of the memory rows include at least one Electrically Erasable Programmable Read-Only Memory (EEPROM) memory element and at least one Flash memory element. The EEPROM and Flash elements are configured to share some of the supporting circuits and can be accessed in parallel.
1. A non-volatile memory circuit, the non-volatile memory circuit comprising:
memory rows, wherein at least one of the memory rows comprises at least one Electrically Erasable Programmable Read-Only Memory (EEPROM) memory element and at least one Flash memory element, and wherein the at least one EEPROM element and the at least one Flash element are configured to be accessed in parallel; and
supporting circuits coupled to the memory rows, wherein some of the supporting circuits are shared by the at least one EEPROM element and the at least one Flash element of the at least one of the memory rows.
2. The non-volatile memory circuit of claim 1 , wherein each of the at least one EEPROM memory element comprises one or more EEPROM memory cells, wherein each of the at least one Flash element comprises one or more Flash memory cells, wherein each of the one or more EEPROM memory cells comprises an EEPROM cell transistor, and wherein each of the one or more Flash memory cells comprises a Flash cell transistor, wherein each of the memory rows comprises the at least one EEPROM memory element and the at least one Flash memory element, and wherein the heights of the memory rows are identical to each other.
3. The non-volatile memory circuit of claim 2 , wherein each of the at least one EEPROM memory element is configured to store a data word, and wherein each of the at least one Flash element is configured to store another data word.
4. The non-volatile memory circuit of claim 2 , wherein each of the one or more EEPROM memory cells further comprises an access transistor, and wherein each of the one or more Flash memory cells further comprises another access transistor.
5. The non-volatile memory circuit of claim 4 , wherein the access transistors are coupled to a voltage supply line and are configured to select each EEPROM cell transistor and each Flash cell transistor of the memory row when the voltage supply line is activated.
6. The non-volatile memory circuit of claim 5 , wherein the at least one of the memory rows further comprises selection transistors, and wherein each of the selection transistors is coupled to a second voltage supply line and to one of the EEPROM memory elements.
7. The non-volatile memory circuit of claim 6 , wherein the selection transistors are configured to be activated to connect the second voltage supply line to one of the EEPROM memory elements and to be deactivated to separate the second voltage supply line from one of the EEPROM memory elements.
8. The non-volatile memory circuit of claim 7 , wherein the Flash cell transistors of the Flash memory cells are coupled to a third voltage supply line and are configured to be accessible when the third voltage supply line is activated.
9. The non-volatile memory circuit of claim 2 , wherein the at least one of the memory rows comprises only one EEPROM memory element.
10. The non-volatile memory circuit of claim 1 , wherein the supporting circuits comprise a sense amplifier configured to measure a voltage or a current of the at least one EEPROM element or the at least one Flash element, a mode selection circuit configured to generate a signal to select the at least one EEPROM element, the at least one Flash element, or the at least one EEPROM element and the at least one Flash element in parallel, and power supply circuits configured to provide power to the at least one EEPROM element and the at least one Flash element.
11. The non-volatile memory circuit of claim 1 further comprising:
an address bus configured to receive a memory address;
a column decoder coupled to the address bus and configured to select at which memory column an EEPROM memory element or a Flash memory element that corresponds to the memory address is located; and
a row decoder coupled to the address bus and configured to select at which memory row the EEPROM memory element or the Flash memory element that corresponds to the memory address is located.
12. A non-volatile memory circuit, the non-volatile memory circuit comprising:
an Electrically Erasable Programmable Read-Only Memory (EEPROM) memory matrix;
a Flash memory matrix;
an address bus configured to receive a memory address;
a column decoder coupled to the address bus and configured to select at which memory column a memory element that corresponds to the memory address is located; and
a row decoder coupled to the address bus and configured to select at which memory row the memory element that corresponds to the memory address is located,
wherein at least one row of the non-volatile memory circuit comprises at least one EEPROM memory element from the EEPROM memory matrix and at least one Flash memory element from the Flash memory matrix, and wherein the at least one EEPROM memory element and the at least one Flash memory element from the Flash memory matrix are configured to be accessed in parallel.
13. The non-volatile memory circuit of claim 12 , wherein each of the at least one EEPROM memory element comprises one or more EEPROM memory cells, wherein each of the at least one Flash element comprises one or more Flash memory cells, wherein each of the one or more EEPROM memory cells comprises an EEPROM cell transistor, and wherein each of the one or more Flash memory cells comprises a Flash cell transistor, wherein each memory row of the non-volatile memory circuit comprises the at least one EEPROM memory element and the at least one Flash memory element, and wherein the heights of memory rows of the non-volatile memory circuit are identical to each other.
14. The non-volatile memory circuit of claim 13 , wherein each of the one or more EEPROM memory cells further comprises an access transistor, wherein each of the one or more Flash memory cells further comprises another access transistor, wherein the access transistors are coupled to a voltage supply line and are configured to select each EEPROM cell transistor and each Flash cell transistor of the at least one memory row when the voltage supply line is activated, wherein the at least one memory row further comprises selection transistors, wherein each of the selection transistors is coupled to a second voltage supply line and to one of the EEPROM memory elements, wherein the selection transistors are configured to be activated to connect the second voltage supply line to one of the EEPROM memory elements and to be deactivated to separate the second voltage supply line from one of the EEPROM memory elements, and wherein the Flash cell transistors of the Flash memory cells are coupled to a third voltage supply line and are configured to be accessible when the third voltage supply line is activated.
15. The non-volatile memory circuit of claim 12 , wherein each of the at least one EEPROM memory element is configured to store a data word, and wherein each of the at least one Flash element is configured to store another data word.
16. The non-volatile memory circuit of claim 12 , wherein the at least one memory row comprises only one EEPROM memory element.
17. The non-volatile memory circuit of claim 12 , wherein the row decoder comprises a decoding circuit and level shifter circuits for the at least one memory row.
18. The non-volatile memory circuit of claim 12 further comprising supporting circuits coupled to the EEPROM memory matrix and the Flash memory matrix, wherein some of the supporting circuits are shared by the at least one EEPROM element and the at least one Flash element of the at least one of the memory rows.
19. A method for accessing data stored in a non-volatile memory circuit, the method comprising:
selecting all Electrically Erasable Programmable Read-Only Memory (EEPROM) memory cells and all Flash memory cells in a memory row of a memory circuit;
supplying a first voltage to the selected Flash memory cells;
supplying a second voltage to at least some of the selected EEPROM memory cells; and
accessing data stored in the selected Flash memory cells and data stored in the at least some of the selected EEPROM memory cells.
20. The method of claim 19 , wherein supplying the second voltage to the at least some of the selected EEPROM memory cells comprises supplying the second voltage to the selected EEPROM memory cells through selection transistors, wherein supplying the second voltage to the at least some of the selected EEPROM memory cells further comprises activating or deactivating the selection transistors, and wherein accessing data stored in the selected Flash memory cells and data stored in the at least some of the selected EEPROM memory cells comprises at least one of:
reading the data stored in the selected Flash memory cells and the data stored in the at least some of the selected EEPROM memory cells;
erasing the data stored in the selected Flash memory cells and the data stored in the at least some of the selected EEPROM memory cells; and
writing new data into the selected Flash memory cells and the at least some of the selected EEPROM memory cells,
wherein each memory row of the memory circuit comprises the EEPROM memory cells and the Flash memory cells, and wherein the heights of memory rows of the memory circuit are identical to each other.