Memory module decoder

• US 7,864,627 B2
• Filed: 10/12/2009
• Issued: 01/04/2011
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: Netlist, Inc.
• Original Assignee: Netlist, Inc.
• Inventors: Solomon, Jeffrey C., Bhakta, Jayesh R.
• Primary Examiner(s): Sofocleous; Alexander
• Application Number:
  US12/577,682
• Publication Number:
  US 20100091540A1
• Time in Patent Office: 449 Days
• Field of Search: 365/51, 365/149, 365/230.03, 365/230.06, 365/233.13
• US Class Current: 365/233.13
• CPC Class Codes: G06F 12/0207 with multidimensional access, e.g. row/column, matrix
• CPC Class Codes: G06F 12/0215 with look ahead addressing means
• CPC Class Codes: G11C 2207/105 Aspects related to pads, pins or terminals
• CPC Class Codes: G11C 5/04 Supports for storage elements , e.g. memory modules; Mounting or fixing of storage elements on such supports
• CPC Class Codes: G11C 5/066 Means for reducing external access-lines for a semiconductor memory clip, e.g. by multiplexing at least address and data signals
• CPC Class Codes: G11C 7/1048 Data bus control circuits, e.g. precharging, presetting, equalising
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10159 Memory
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A circuit is configured to be mounted on a memory module connectable to a computer system so as to be electrically coupled to a plurality of memory devices on the memory module. The plurality of memory devices has a first number of memory devices. The circuit comprises a logic element configurable to receive a set of input signals from the computer system. The circuit further comprising a register and a phase-lock loop circuit, the phase-lock loop circuit configurable to be operatively coupled to the plurality of memory devices, the logic element, and the register. The set of input signals corresponds to a second number of memory devices smaller than the first number of memory devices.

Claims

1. A circuit configured to be mounted on a memory module so as to be electrically coupled to a first number of double-data-rate (DDR) memory devices arranged in a first number of ranks on the memory module, the memory module configured to be electrically coupled to a memory controller of a computer system so as to receive a set of input signals from the computer system, the set of input signals comprising row/column address signals, bank address signals, and chip-select signals, the set of input signals corresponding to a second number of DDR memory devices arranged in a second number of ranks, the second number of DDR memory devices smaller than the first number of DDR memory devices and the second number of ranks less than the first number of ranks, the circuit comprising:

a logic element configurable to receive the set of input signals;

a register; and

a phase-lock loop circuit configurable to be operatively coupled to the first number of DDR memory devices, the logic element, and the register,

wherein the circuit is configurable to generate a set of output signals in response to the set of input signals, the set of output signals corresponding to the first number of DDR memory devices arranged in the first number of ranks, wherein the circuit is configurable to further respond to the set of input signals from the computer system by generating and transmitting the set of output signals to the first number of DDR memory devices.

2. The circuit of claim 1, wherein the set of input signals comprises a first number of chip-select signals and wherein the set of output signals comprises a second number of chip-select signals greater than the first number of chip-select signals.

3. The circuit of claim 2, wherein the first number of chip-select signals is two.

4. The circuit of claim 1, wherein the circuit is configurable to receive and buffer a plurality of row/column address signals of the input signals during a row access procedure and to use the buffered plurality of row/column address signals during a subsequent column access procedure.

5. The circuit of claim 1, wherein the logic element comprises an application-specific integrated circuit, a field-programmable gate array, a custom-designed semiconductor device, or a complex programmable-logic device.

6. The circuit of claim 1, wherein the bank address signals of the set of input signals are received by both the logic element and the register.

7. The circuit of claim 1, wherein two or more of the phase-lock loop circuit, the register, and the logic element are portions of a single component.

8. The circuit of claim 1, wherein the register comprises a plurality of register circuits.

9. The circuit of claim 1, wherein the plurality of DDR memory devices comprises a plurality of DDR3 memory devices.

10. The circuit of claim 1, wherein the set of input signals corresponds to a first memory density per rank, and the set of output signals corresponds to a second memory density per rank, the second memory density per rank less than the first memory density per rank.

11. The circuit of claim 1, wherein the circuit is configurable to further respond to the set of input signals from the computer system by selecting at least one rank of the first number of ranks and transmitting the set of output signals to at least one DDR memory device of the selected at least one rank of the first number of ranks.

12. The circuit of claim 1, wherein the circuit is configurable to store an input signal of the set of input signals during a row access procedure for subsequent use during a column access procedure.

13. A circuit configured to be mounted on a memory module so as to be electrically coupled to a first number of double-data-rate (DDR) memory devices arranged in a first number of ranks on the memory module, the memory module configured to be electrically coupled to a memory controller of a computer system so as to receive a set of input signals from the computer system, the set of input signals comprising at least one row/column address signal, bank address signals, and at least one chip-select signal, the set of input signals configured to control a second number of DDR memory devices arranged in a second number of ranks, the second number of DDR memory devices smaller than the first number of DDR memory devices and the second number of ranks less than the first number of ranks, the circuit comprising:

a logic element configurable to receive the set of input signals;

a register; and

a phase-lock loop circuit configurable to be operatively coupled to the first number of DDR memory devices, the logic element, and the register,

wherein the circuit is configurable to generate a set of output signals in response to the set of input signals, the set of output signals configured to control the first number of DDR memory devices arranged in the first number of ranks, wherein the circuit is configurable to transmit the set of output signals to the first number of DDR memory devices.

14. The circuit of claim 13, wherein the set of input signals comprises a number of chip-select signals and wherein the set of output signals comprises more chip-select signals than the number of chip-select signals.

15. The circuit of claim 13, wherein the circuit is configurable to store an input signal of the set of input signals during a row access procedure for subsequent use during a column access procedure.

16. The circuit of claim 13, wherein the circuit is configurable to select at least one rank of the first number of ranks and to transmit the set of output signals to at least one DDR memory device of the selected at least one rank of the first number of ranks.

17. The circuit of claim 13, wherein two or more of the phase-lock loop circuit, the register, and the logic element are portions of a single component.

18. The circuit of claim 13, wherein the set of input signals corresponds to a first memory density per rank, and the set of output signals corresponds to a second memory density per rank, the second memory density per rank less than the first memory density per rank.

19. A circuit configured to be mounted on a memory module so as to be electrically coupled to a first number of double-data-rate (DDR) memory devices arranged in a first number of ranks on the memory module, the first number of ranks selectable by a first number of chip-select signals, the memory module configured to be electrically coupled to a memory controller of a computer system so as to receive a set of input signals from the computer system, the set of input signals comprising row address signals, column address signals, bank address signals, and a second number of chip-select signals less than the first number of chip-select signals, the set of input signals configured to utilize a second number of DDR memory devices arranged in a second number of ranks, the second number of DDR memory devices smaller than the first number of DDR memory devices and the second number of ranks less than the first number of ranks, the circuit comprising:

a logic element configurable to receive the set of input signals;

a register; and

a phase-lock loop circuit configurable to be operatively coupled to the first number of DDR memory devices, the logic element, and the register,

wherein the circuit is configurable to generate a set of output signals in response to the set of input signals, the set of output signals comprising the first number of chip-select signals and configured to utilize the first number of DDR memory devices arranged in the first number of ranks.

20. The circuit of claim 19, wherein two or more of the phase-lock loop circuit, the register, and the logic element are portions of a single component.