Abstract: The present disclosure is directed to a method of utilizing a lookup table (LUT) where the index to the LUT does not need to be modified or changed in cases where the LUT is larger than a single register or larger than a set of available registers. In another embodiment, a processor instruction is disclosed that can take in one or more indices to a LUT and return the lookup results, without modifying the indices, when the LUT is larger than the available register data element space. In another embodiment, a SIMD processor system is disclosed that can implement a processor instruction to utilize a LUT that is larger than the available register data element space without needing to modify the parameterized index when a different subset of the LUT is swapped into the available registers.

Abstract: A system and method for determining the impedance of a telephone transmission line are disclosed. A test signal is transmitted through a telephone switch to the telephone line and corresponding echo signals are monitored. The test and echo signals are correlated to derive an impulse response. A transfer function for the system is calculated from the impulse response. Then, a transfer function for the transmission line is derived using the system transfer function and the transfer function of the telephone switch. Finally, the transmission line impedance is calculated from the transmission line transfer function. Once the transmission line impedance is known, an impedance matching circuit for the telephone switch can be modified to match the transmission line and the switch.