A programmable analog coprocessor
Joseph P. Heid · 2002
This paper describes the general purpose hardware/software structure of a programmable analog coprocessor (PANCoP) and the functions it performs as a symbiotic interface with a modest but fast 16 bit microprocessor. This paper describes the features of this complementary computer combination that serves as a versatile processor suitable for real-time, analog oriented applications. It describes how PANCoP is programmed to operate either as an interactive processor/interface that shares the computational workload with the microprocessor, or as an independent processor that directly assumes the full workload. The paper describes how the two computers complement each other in the efficient execution of application programs. Specifically, the performance characteristics (instruction execution times and accuracies) of a prototype PANCoP unit, using discrete ICs, are described and compared with those of more conventional designs using AD/DA converters that are noncontributors in terms of computing power. This paper describes: (1) the list of IC component types comprising the PANCoP prototype design; (2) the transfer functions that are executed by PANCoP's core unit, the hybrid arithmetic unit (HAU); (3) PANCoP subroutines that execute higher level arithmetic functions; (4) assembler/compiler programming aids; and (5) the design challenges that remain to be addressed in order to make PANCoP competitive with conventional designs.