Multifunctional combined testing moving group chain device

Abstract

The present invention discloses a multi-function JTAG chain device comprising a boundary scan connector that is used for boundary scanning and at least two JTAG components which are connected to form a JTAG chain and are connected with the boundary scan connector. The device also comprises a controllable switch, a switch control device and a debugging connector that serves for the downloading and debugging of each JTAG component. A controllable switch is arranged in series respectively between the test data input TDI pin of the boundary scan connector and TDI pin of the JTAG component that is connected with the boundary scan connector; between test data output TDO pins in series of the JTAG chain and TDI pin; between TDO pins of the boundary scan connector and TDO pins of the JTAG component; and in each parallel-connection branch lines formed by the test mode selection input TMS/test clock input TCK pins and TMS/TCK pins of each JTAG component. All controllable switches are all under the control of the switch control device; TDI, TDO, TMS and TCK pins of each JTAG component are connected respectively with TDI, TDO, TMS and TCK pins of the debugging connector.

Description

technical field [0001] The invention relates to a joint test action group (JTAG, Joint Test Action Group) connection technology, in particular to a multifunctional JTAG chain device. Background technique [0002] JTAG is an international standard test protocol, mainly used for chip internal testing. At present, many complex devices support the JTAG protocol, such as DSP, FPGA and other devices. Generally, such devices supporting the JTAG protocol are called JTAG devices. The standard JTAG interface is 4 lines, including test mode selection input line (TMS), test clock input line (TCK), test data input line (TDI) and test data output line (TDO). It is very convenient to download and debug JTAG devices through the debug connector. [0003] What Figure 1 shows is a schematic diagram of the connection between the debug connector and the JTAG device. In FIG. 1 , the circuit includes three JTAG devices, namely JTAG device 101, JTAG device 103 and JTAG device 105, and three corr...

AI Technical Summary

Problems solved by technology

[0007] At present, there is a lack of a JTAG chain that not only supports the boundary scan test of the circuit, but also supports the download and debugging of JTAG devices using different debug connectors.

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