NL09H1XX
Hybrid analog/digital data processor
Development Boards

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NL09H1XX Datasheet (7/1/09)
PDF 1.4 MB

Design principles and operation

The NL09H1XX development boards implement hybrid signal processing, in modules that are appropriate for various applications of topologic. The basic idea of topologic is that a system can be resolved into a relatively large number of relatively small units. Simple circuit fragments are defined that are electronic analogues of the system units. By connecting the circuit fragments together with the same topology as the system, a complete circuit is obtained that is an electronic analogue of the system. We call such circuits circuit systems. The circuit behavior is guaranteed to correspond to the behavior of the system, because every part of the circuit is the analogue of a corresponding part of the system.

The following figure shows a block diagram of the core circuit used in these products:

This circuit is hybrid: it makes use of an ADC and a digital microprocessor MP to digitize and store analog input. The MP is used to perform transformations (functions) of the stored data. LEDs are used to monitor the values of variables, in particular the digital input to the DAC. Although we are primarily interested in processing analog signals, we do include digital data input, for versatility. The digital data output is used for control signals, e.g., for reconfiguring the circuits, testing for criteria satisfactions, etc.

The circuit can be used to emulate other NanoLogic analog computational circuits, including the NL09D1XX series for chaotic dynamics, and the NL09S1XX series for finite set theory. For dynamics, this circuit will generate a complex function that could represent the nonlinear behavior of a complex physical system. For set theory, the MP memory will hold a characteristic function of a crisp set, i.e., a Boolean function that gives TRUE if the analog input value is a member of the (stored) set, and FALSE if it is not.

In addition, this circuit can simulate the response of nanoelectronic devices, by storing and manipulating nonlinear characteristic transfer functions. Since we envision the stacking of nanoscale devices to form compound devices, with no access or control to the individual devices, we need a means to combine complex nonlinear transfer functions to form equivalent transfer functions that can be simplified to conform to a defined analog precision. The digital memory of the MP in the NL09HXX circuits makes this an easy task.

The limitation of these circuits is that they are relatively slow compared to programmable high-speed data processors. However, these modules are meant for research and development, not production. In particular, they are meant to assist in developing algorithms for analog data processing using hardware designed with the topologic paradigm.

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The NL09H1XX product series provides several implementations of circuit systems, using the topologic design principle. Signals are provided to pins that enable jumper connections within the modules and to other modules. Overlay boards are available that provide default connections for some common connectivities, eliminating the need for extensive manual jumper wiring.

The NL09H101 board comprises a microprocessor MCU containing a 10-bit ADC, and an external 10-bit parallel input DAC. The 10-bit LED stack displays the word input to the DAC. The data and other signals are provided on pins to enable connecting to other circuits with jumpers. A 20-conductor cable provides the signal inputs, which consist of up to 4 analog signals, a 10-bit digital word, and 6 additional signals that can be used for control and communication.

The input and output cabling on the NL09H101 are coherent, allowing multiple units to be connected directly out-to-in. The following figure shows 4 modules connected in a linear array:

The NL09H108 board comprises 8 of the NL09H101 units, each with the MCU and DAC, and a set of LED indicators. The board connector provides programming for the MCUs, the data bus, and power. Connection between the units is done using jumpers on the backplane. A connector at the top edge provides an alternative source of signals for imaging or monitoring.