Method and apparatus for providing pseudo 2-port RAM functionality using a 1-port memory cell
View Patent ↗A method and apparatus operable to provide pseudo 2-port RAM functionality using 1-port memory cells. A pseudo 2-port RAM functionality is provided using an array of 1-port memory cells to perform read and write operations during a single clock cycle. Control logic is used to determine when the read and write operations occur. The pseudo 2-port RAM uses the control logic to divide the clock cycle into four phases in accordance with a preferred embodiment. The first phase is used to set up the addresses and register values, the second phase is used to prepare for the read operation, the third phase is used to perform the read operation and prepare for the write operation, and the fourth phase performs the write operation.
1. A random access memory (RAM) having a plurality of one-port memory cells and a control logic element operable to manipulate timing of a system clock internal to the RAM to provide each one-port memory cell of the plurality of one-port memory cells a read operation capability and a write operation capability during a single cycle of the system clock wherein at least a portion of the read operation capability occurs concurrently with the write operation capability.
2. The apparatus of claim 1 , wherein the random access memory is a static random access memory (SRAM).
3. The apparatus of claim 1 , wherein the read operation capability occurs prior to the write operation capability.
4. The apparatus of claim 1 , the random access memory further comprising:
a final decode and one or more column muxes, coupled to the plurality of one port memory cells;
one or more sense amps, coupled to the final decode and coupled to the one or more column muxes;
one or more write drivers, coupled to the final decode and coupled to the one or more column muxes;
one or more input registers coupled to the one or more write drivers, said one or more input registers operable to be coupled to one or more input data; and
one or more output registers coupled to the one or more sense amps, said one or more output registers operable to be coupled to one or more output data.
5. The apparatus of claim 4 , wherein the one or more output registers are coupled to one or more output drivers prior to being coupled to the one or more output data.
6. The apparatus of claim 4 , wherein the control logic element is coupled to one or more of:
the final decode and the one or more column muxes;
the one or more sense amps;
the one or more write drivers;
the one or more input registers; and
the one or more output registers.
7. The apparatus of claim 6 , wherein one or more timing signals and one or more control signals of the control logic element are operable to be generated using one or more of a system clock and a delayed system clock.
8. The apparatus of claim 1 , the random access memory further comprising:
plurality of bitline precharges and a plurality of rowline drivers, said plurality of bitline precharges and plurality of rowline drivers coupled to the plurality of one port memory cells;
one or more row decoders and one or more column decoders, coupled to the plurality of bitline precharges and the plurality of row drivers; and
one or more address registers, coupled to the one or more row decoders and the one or more column decoders and the plurality of row drivers, said one or more address registers further coupled to a read address and a write address.
9. The apparatus of claim 8 , wherein the control logic element is coupled to one or more of:
the plurality of bitline precharges and the one or more rowline drivers;
the one or more row decoders and the one or more column decoders; and
one or more address registers.
10. A random access memory (RAM) capable of performing one or more of a one or more read operations and a one or more write operations during a single cycle of a clock signal, wherein a read operation of the one or more read operations and a write operation of the one or more write operations use a one-port memory cell of a plurality of one-port memory cells, comprising a control logic element of the RAM operative to control a timing of operation of a read functionality of the one-port memory cell and a write functionality of the one-port memory cell, a sense amplifier element coupled to the one-port memory cell to enable a read operation and a write driver element coupled to the one-port memory cell to enable a write operation, wherein the read operation and the write operation occur during the single cycle of the clock signal and wherein at least a portion of said read operation occurs concurrently with said write operation.
11. The apparatus of claim 10 , wherein the RAM is a static RAM (SRAM).
12. The apparatus of claim 10 , wherein the clock signal and one or more control signals of the control logic element are operable to be generated using one or more of a system clock and a delayed system clock.
13. The apparatus of claim 12 , wherein the system clock is provided to one or more of:
one or more read enable registers;
one or more write enable registers;
one or more read addresses;
one or more write addresses;
one or more input registers; and
one or more output registers.
14. The apparatus of claim 10 , wherein the read functionality further comprises:
a plurality of bitline precharges and a plurality of rowline drivers, said plurality of bitline precharges and plurality of rowline drivers coupled to the plurality of one port memory cells;
one or more row decoders and one or more column decoders, said one or more row decoders coupled to the plurality of rowline drivers and said one or more column decoders coupled to the plurality of bitline precharges;
one or more address registers, coupled to the one or more column decoders and coupled to the one or more row decoders, said one or more address registers further coupled to a read address and a write address;
one or more sense amps, coupled to the plurality of bitline precharges and coupled to the one or more output registers; and
the one or more output registers operable to be coupled to one or more output data.
15. The apparatus of claim 14 , wherein the one or more output registers are coupled to one or more output drivers prior to being coupled to the one or more output data.
16. The apparatus of claim 14 , wherein the control logic element is coupled to one or more of:
the plurality of bitline precharges;
the one or more address registers;
the one or more row decoders and the one or more column decoders;
the one or more row drivers;
the one or more sense amps; and
the one or more output registers.
17. The apparatus of claim 10 , wherein the write functionality further comprises:
a plurality of bitline precharges and a plurality of rowline drivers, said plurality of bitline precharges and plurality of row drivers coupled to the plurality of one port memory cells;
one or more row decoders and one or more column decoders, coupled to the plurality of rowline drivers and the plurality of bitline precharges;
one or more address registers, coupled to the one or more row decoders and coupled to the one or more column decoders, said one or more address registers further coupled to a read address and a write address;
one or more write drivers, coupled to the plurality of bitline precharges and coupled to one or more input registers; and
the one or more input registers operable to be coupled to one or more input data.
18. The apparatus of claim 17 , wherein the control logic element is coupled to one or more of:
the plurality of bitline precharges and the one or more rowline drivers;
one or more address registers;
the one or more row decoders and the one or more column decoders;
the one or more write drivers; and
the one or more input registers.