Adjustable drive strength input-output buffer circuitry
View Patent ↗An integrated circuit in a multi-chip package is provided. The integrated circuit may include adjustable interface circuitry configured to interface with other off-chip components. In particular, the adjustable interface circuitry may include a microbump input-output buffer operable to drive signals off of the integrated circuit and operable to receive signals from other integrated circuits in the multi-chip package via a microbump. The microbump input-output buffer may include output buffers and input buffers. The output buffers may have programmable drive strengths and may each be selectively switched in and out of use depending on the desired application. Each output buffer may include a level shifter, a buffer circuit, and multiple inverter-like circuits each of which can be turned on or off to adjust the drive strength of that output buffer.
1. An integrated circuit within a multi-die package comprising:
a microbump pad that is coupled to another integrated circuit in the multi-die package;
a flip-chip bump pad;
a microbump output buffer circuit that is coupled to the microbump pad, wherein the microbump output buffer circuit has an adjustable drive strength and wherein the microbump output buffer circuit drives output signals to the another integrated circuit;
a flip-chip bump output buffer circuit that is coupled to the flip-chip bump pad; and
a control circuit that generates control signals that control the adjustable drive strength of the microbump output buffer circuit.
2. The integrated circuit defined in claim 1 , wherein the flip-chip bump output buffer circuit has an adjustable drive strength, and wherein the control circuit further generates control signals that control the adjustable drive strength of the flip-chip bump output buffer circuit.
3. The integrated circuit defined in claim 1 , further comprising:
a microbump input buffer circuit that is coupled to the microbump pad.
4. The integrated circuit defined in claim 1 , wherein the microbump output buffer circuit comprises a plurality of output buffers, wherein each output buffer in the plurality of output buffers has a different respective gate oxide thickness.
5. The integrated circuit defined in claim 4 further comprising:
a microbump input buffer circuit that is coupled to the microbump pad, wherein the microbump input buffer circuit includes a plurality of input buffers, wherein each input buffer in the plurality of input buffers has a different respective gate oxide thickness.
6. The integrated circuit defined in claim 1 , wherein the microbump output buffer circuit comprises:
a plurality of output buffers, wherein each output buffer in the plurality of output buffers has an adjustable drive strength.
7. The integrated circuit defined in claim 6 further comprising:
a microbump input buffer circuit that is coupled to the microbump pad, wherein the microbump input buffer circuit includes a plurality of input buffers, and wherein each input buffer in the plurality of input buffers has a fixed drive strength.
8. The integrated circuit defined in claim 1 , wherein the flip-chip bump pad is larger than the microbump pad.
9. The integrated circuit defined in claim 1 , further comprising:
a through-silicon via that connects the microbump pad to another integrated circuit above the integrated circuit.
10. An integrated circuit comprising:
a microbump pad;
a microbump output buffer circuit that is coupled to the microbump pad, wherein the microbump output buffer circuit has a programmable drive strength and wherein the microbump output buffer circuit comprises a plurality of inverter-like circuits coupled between a signal terminal and the microbump pad; and
a control circuit that generates control signals that control the programmable drive strength of the microbump output buffer circuit by switching individual inverter-like circuits from the plurality of inverter-like circuits in and out of use.
11. The integrated circuit defined in claim 10 , further comprising:
a flip-chip bump pad; and
a flip-chip bump output buffer circuit that is coupled to the flip-chip bump pad.
12. The integrated circuit defined in claim 10 , further comprising:
an input buffer that receives signals from external circuitry.
13. An integrated circuit comprising:
an input-output pad;
an output buffer that is coupled to the input-output pad, wherein the output buffer has adjustable drive strength; and
a plurality of input buffers that are coupled to the input-output pad, wherein each input buffer of the plurality of input buffers has a respective fixed drive strength, and wherein at least first and second input buffers in the plurality of input buffers have different respective fixed drive strengths; and
a control circuit that generates control signals for controlling the adjustable drive strength of the output buffer.
14. The integrated circuit defined in claim 13 , further comprising:
a through-silicon via that connects the input-output pad to another integrated circuit above the integrated circuit.