Data Acquisition Using INS8048
This application note describes techniques for interfacing National Semiconductor's ADC0833 serial I/O, and ADC0804 parallel I/O A/D converters to the INS8048 family of microprocessors. A hardware and software interface example is provided for each A/D, along with a brief theory of operation.
Since the INS8048 series microprocessors are single-chip, multiple I/O line, high speed devices designed as efficient controllers, the capacity to interface with analog peripherals is obvious. That the conversion be fast, inexpensive and easily expanded to accommodate a number of I/O devices is desirable.
The INS8048 is a self-contained, 8-bit processor in a 40-pin dual-in-line package. It contains its own system timing, control logic and memory. All parts contain RAM (64, 128, 256 bytes) and offer the option of on-board ROM (1k, 2k, 4k depending on part). It provides extensive bit-handling capabilities, 97 instructions, and offers easy expansion for I/O and memory. The ADC0833 A/D converter is an 8-bit successive-approximation device with serial I/O and conversion time of 25 ms.
This family of converters offers various configurations of multiplexed analog inputs which can be software programmed as single-ended, or as differential inputs, or both. Single-ended inputs are referenced to a common pin which is either referred to analog ground or to a fixed reference voltage. Like the INS8048 family, a single 5V power supply is all that is needed. The inputs will accept a 0V-5V range. No zero adjust is necessary. It is compatible with TTL and MOS at both input and output. The output can be selected as either MSB or LSB first.
Since the INS8048 series microprocessors are single-chip, multiple I/O line, high speed devices designed as efficient controllers, the capacity to interface with analog peripherals is obvious. That the conversion be fast, inexpensive and easily expanded to accommodate a number of I/O devices is desirable.
The INS8048 is a self-contained, 8-bit processor in a 40-pin dual-in-line package. It contains its own system timing, control logic and memory. All parts contain RAM (64, 128, 256 bytes) and offer the option of on-board ROM (1k, 2k, 4k depending on part). It provides extensive bit-handling capabilities, 97 instructions, and offers easy expansion for I/O and memory. The ADC0833 A/D converter is an 8-bit successive-approximation device with serial I/O and conversion time of 25 ms.
This family of converters offers various configurations of multiplexed analog inputs which can be software programmed as single-ended, or as differential inputs, or both. Single-ended inputs are referenced to a common pin which is either referred to analog ground or to a fixed reference voltage. Like the INS8048 family, a single 5V power supply is all that is needed. The inputs will accept a 0V-5V range. No zero adjust is necessary. It is compatible with TTL and MOS at both input and output. The output can be selected as either MSB or LSB first.
Data Acquisition Using INS8048
Reviewed by haru
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March 26, 2009
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