Memory circuitry with row-wise gating capabilities
An integrated circuit that includes an array of random-access memory cells is provided. Each memory cell in the array may be a single-port or a multiport memory cell. Memory cells in the same column of the array are connected to shared bit lines, whereas memory cells in the same row of the array are connected to shared word lines. The memory cells in the same row may also be connected to a row control line. During normal operations, the row control line may provide a positive power supply voltage to each memory cell along that row. During write operations, the row control line may be driven to ground or tri-stated to help improve the write margin and the write performance of the selected memory cells. The aspect ratio of these memory cells may also be more square-like or balanced to help improve power delivery.
1. An integrated circuit, comprising:
an array of memory cells arranged in rows and columns, wherein each memory cell in the array includes inverting circuits having a power supply terminal; and
power supply gating circuitry that is coupled to the power supply terminal in each memory cell along a selected row of memory cells in the array, wherein:
the power supply gating circuitry is activated when writing data into the selected row of memory cells;
when the power supply gating circuitry is deactivated, the power supply gating circuitry provides a positive power supply voltage to the power supply terminal in each memory cell along the selected row; and
when the power supply gating circuitry is activated, the power supply gating circuitry provides a ground power supply voltage to the power supply terminal in each memory cell along the selected row.
2. The integrated circuit of claim 1 , wherein the array of memory cells comprises an array of random-access memory cells.
3. The integrated circuit of claim 2 , wherein the random-access memory cells comprises multiport memory cells.
4. The integrated circuit of claim 1 , further comprising:
a word line that is coupled to the selected row of memory cells; and
a delay circuit that is coupled between the word line and the power supply terminal in each memory cell along the selected row.
5. The integrated circuit of claim 4 , wherein the delay circuit comprises an inverter.
6. The integrated circuit of claim 1 , wherein the selected row of memory cells receives a word line signal and also receives a gated power supply signal at the power supply terminal, and wherein the word line signal is a delayed and inverted version of the gated power supply signal.
7. An integrated circuit, comprising:
an array of memory cells arranged in rows and columns, wherein each memory cell in the array includes inverting circuits having a power supply terminal; and
power supply gating circuitry that is coupled to the power supply terminal in each memory cell along a selected row of memory cells in the array, wherein the power supply gating circuitry is activated when writing data into the selected row of memory cells, and wherein when the power supply gating circuitry is activated, the power supply gating circuitry tri-states the power supply terminal in each memory cell along the selected row.
8. The integrated circuit of claim 7 , further comprising:
a word line that is coupled to the selected row of memory cells; and
a shared pull-up transistor having a gate terminal that is connected to the word line and a drain terminal that is connected to the power supply terminal in each memory cell along the selected row.
9. The integrated circuit of claim 1 or 7 , wherein each memory cell in the array has a square-like layout.
10. A method of operating an integrated circuit that includes an array of memory cells, the method comprising:
presenting write data values to the array of memory cells;
gating a power supply line that powers a selected row of memory cells in the array;
asserting a word line signal for the selected row of memory cells, wherein the word line signal also controls the gating of the power supply line; and
while the power supply line is being gated for the selected row of memory cells, loading the write data values into the selected row of memory cells in the array.
11. The method of claim 10 , wherein gating the power supply line comprises providing a ground power supply voltage to the selected row of memory cells.
12. The method of claim 10 , wherein gating the power supply line comprises at least partially cutting off a pull-up current path for the selected row of memory cells.
13. The method of claim 10 , further comprising:
after gating the power supply line, providing a positive power supply voltage to the selected row of memory cells.
14. The method of claim 10 , further comprising toggling the power supply line, wherein the word line signal is asserted in response to toggling the power supply line.