JTAG (Joint Test Action Group) isolation circuit used for DSP (Digital Signal Processor)

Abstract

The invention is a JTAG isolation circuit used for a DSP and belongs to the technical field of optoelectronic countermeasure. The circuit uses a DSP, a CPLD (Complex Programmable Logic Device) chip, a conventional isolation transceiver of an integrated power supply, a high-speed isolation transceiver, an on-board JTAG connector and an outside-chassis JTAG connector to form a circuit for isolating JTAG signals. The circuit uses CPLD to achieve the connection and automatic detection and real-time switching of the two inside and outside JTAG connectors, so that the supporting for the on-board JTAG and the JTAG extension of the outside connector can be obtained and the inside and outside JTAG connectors can be easily connected when the single board debugging and the complete machine debugging are performed. In addition, effective isolation protection can be achieved due to the 2000V isolation voltage is supported for the outside JTAG signals and the effective performance of the operation process can be improved owing to the JTAG signals isolation under the condition that the power supply is isolated.

Description

technical field [0001] The invention relates to the technical field of photoelectric countermeasures, in particular to a JTAG isolation circuit for DSP, which can be used for the design of DSP hardware circuits in weapon platforms. Background technique [0002] DSP: Digital Signal Processor, digital signal processor, a type of processor for high-speed digital operations. [0003] JTAG: JTAG is the abbreviation of the initials of the English "Joint Test Action Group (Joint Test Action Organization)", which was established in 1985 and is a PCB and IC testing standard initiated by several major electronics manufacturers. The JTAG proposal was approved by the IEEE in 1990 as the IEEE1149.1-1990 Test Access Port and Boundary Scan Architecture Standard. This standard specifies the hardware and software required to perform boundary scan. Since it was approved in 1990, IEEE supplemented the standard in 1993 and 1995 respectively, forming the current IEEE1149.1a-1993 and IEEE1149.1...

AI Technical Summary

Problems solved by technology

[0007] In many cases, the on-site electromagnetic environment is very complicated, and direct JTAG connection outside can easily lead to damage to the interface chip.

[0008] At the same time, it will be more difficult to connect JTAG when debugging a single board

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