What is claimed is:
1. An electrostatically protected circuit comprising:
an internal circuit electrically connected to a pad; and
an ESD protector, including an electrostatic protection circuit in series with an inductor, having a first terminal electrically connected to the pad and internal circuit and a second terminal electrically connected to an exit path for electrostatic discharge pulses appearing at the pad.
2. The electrostatically protected circuit of claim 1, wherein the inductor has an inductance selected to effectively pass signals having frequencies typical of electrostatic discharge pulses and to effectively block signals having frequencies typical of signals desired to be processed by the internal circuit.
3. The electrostatically protected circuit of claim 1, wherein the inductor has an inductance selected to effectively pass signals near a first frequency and to effectively block signals near a second frequency higher than the first frequency.
4. The electrostatically protected circuit of claim 1, wherein the inductor has an inductance selected to compensate for a characteristic capacitance of the electrostatic discharge protection circuit at frequencies typical of signals desired to be processed by the internal circuit.
5. The electrostatically protected circuit of claim 1, further comprising:
an additional ESD protector, including an electrostatic protection circuit in series with an inductor, having a first terminal electrically connected to the pad and internal circuit and a second terminal electrically connected to an additional exit path for electrostatic discharge pulses appearing at the pad.
6. The electrostatically protected circuit of claim 1, further comprising an additional electrostatic protection circuit having a first terminal electrically connected between the electrostatic protection circuit and the inductor of the ESD protector and a second terminal electrically connected to an additional exit path for electrostatic discharge pulses appearing at the pad.
7. The electrostatically protected circuit of claim 1, wherein the inductor is implemented on an integrated circuit chip.
8. The electrostatically protected circuit of claim 1, wherein the inductor is implemented with integrated circuit bonding wire.
9. The electrostatically protected circuit of claim 1, wherein the inductor is electrically connected to the electrostatic protection circuit via an additional pad.
10. The electrostatically protected circuit of claim 9, further comprising an additional internal circuit electrically connected to the second terminal of the inductor, the additional pad and the electrostatic protection circuit.
11. The electrostatically protected circuit of claim 9, wherein the inductor comprises:
a first bonding wire having first and second ends respectively electrically connected to the additional pad and to a package pin; and
a second bonding wire having first and second ends respectively electrically connected to an auxiliary pad and to the package pin;
wherein the electrostatically protected circuit further comprises an on-chip interconnect electrically connecting the first pad and the auxiliary pad.
12. An electrostatically protected circuit comprising:
an internal circuit electrically connected to a pad;
an inductor having a first terminal electrically connected to the pad and internal circuit and a second terminal electrically connected to a source of reference voltage; and
an electrostatic protection circuit having a first terminal electrically connected to the pad and internal circuit and a second terminal electrically connected to an exit path for electrostatic discharge pulses appearing at the pad.
13. The electrostatically protected circuit of claim 12, further comprising an additional electrostatic protection circuit having a first terminal electrically connected to the pad and internal circuit and a second terminal electrically connected to an additional exit path for electrostatic discharge pulses appearing at the pad.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. In a computer graphics system, a method for calculating a texture-mapping gradient comprising:
calculating constant values for use in a gradient-calculating equation;
passing the constant values to logic configured to calculate the gradient; and
computing the gradient using barycentric coordinates and the calculated constant values.
2. The method of claim 1, wherein calculating constant values comprises using logic in a rasterizer to calculate the constant values.
3. The method of claim 1, wherein passing the constant values to logic comprises passing the constant values to a rational linear interpolator computational logic block.
4. The method of claim 1, further comprising using the gradient to select a texture map.
5. The method of claim 1, wherein calculating constant values more specifically comprises calculating constant values that include at least one selected from the group consisting of Csx, Ctx, Crx, and Cqx, wherein Csx is a constant defining an amount of change in s in the x direction, before perspective correction, wherein Ctx is a constant defining an amount of change in t in the x direction, before perspective correction, wherein Crx is a constant defining an amount of change in r in the x direction, before perspective correction, wherein s, t, and r are texture coordinates, and wherein Cqx is an amount that the perspective correction parameter q changes in the x direction.
6. The method of claim 1, wherein calculating constant values more specifically comprises calculating constant values include at least one selected from the group consisting of Csy, Cty, Cry, and Cqy, wherein Csy is a constant defining an amount of change in s in the y direction, before perspective correction, wherein Cty is a constant defining an amount of change in t in the y direction, before perspective correction, wherein Cry is a constant defining an amount of change in r in the y direction, before perspective correction, wherein s, t, and r are texture coordinates, and wherein Cqy is an amount that the perspective correction parameter q changes in the y direction.
7. The method of claim 1, wherein calculating the gradient more specifically comprises calculating the gradient according to the following equation: GpxCpxCqx(pnqn)qnCqx, wherein Cpx(dadx)dp1(dbdx)dp2, wherein Cqx(dadx)dq1(dbdx)dq2, and wherein dadx and dbdx are constant values for an entire primitive.
8. In a computer graphics system, a method for calculating a texture-mapping gradient, the improvement comprising calculating the texture-mapping gradient utilizing barycentric coordinates.
9. The method of claim 8, further comprising deriving constant values for an entire primitive, wherein the constant values are used in the calculation of the texture-mapping gradient.
10. The method of claim 9, wherein the constant values are used at each pixel location within the primitive to calculate the texture-mapping gradient for that pixel.
11. The method of claim 8, wherein a perspective-corrected texture coordinate and a perspective correction value are used to calculate the texture-mapping gradient for each pixel, wherein the perspective correction is one selected from the group consisting of snqn, tnqn, and rnqn, and the perspective correction value is qn.
12. An apparatus for calculating a texture-mapping gradient comprising:
logic for calculating constant values; and
logic for computing the gradient using barycentric coordinates and the calculated constant values.
13. The apparatus of claim 12, wherein the logic for calculating the constant values resides in a rasterizer.
14. The apparatus of claim 12, wherein the logic for computing the gradient-calculating equation resides in a rational linear interpolator computational logic block.
15. The apparatus of claim 12, wherein the constant values include at least one selected from the group consisting of Csx, Ctx, Crx, and Cqx, wherein Csx is a constant defining an amount of change in s in the x direction, before perspective correction, wherein Ctx is a constant defining an amount of change in t in the x direction, before perspective correction, wherein Crx is a constant defining an amount of change in r in the x direction, before perspective correction and wherein Cqx is an amount that the perspective correction parameter q changes in the x direction.
16. A computer-readable medium comprising program code for calculating a texture-mapping gradient, the computer-readable medium comprising:
a segment for generating logic to calculate constant values; and
a segment for generating logic to compute the gradient using barycentric coordinates and the calculated constant values.