JTAG
![](/Images/godic/202501/21/Jtag_chain.svg1926.png")
![A Netgear FVS336G firewall with a 14 pin JTAG header at lower left.](/Images/godic/202501/21/Netgear_ProSafe_Dual_WAN_VPN_Gigabit_Firewall_FVS336G_JTAG_interface1926.jpeg")
![A Netgear DG632 ADSL modem with an 8 pin JTAG header at location](/Images/godic/202501/21/ADSL_modem_router_internals_labeled1926.jpg")
The Joint Test Action Group (JTAG) is an electronics industry association formed in 1985 for developing a method of verifying designs and testing printed circuit boards after manufacture. In 1990 the Institute of Electrical and Electronics Engineers codified the results of the effort in IEEE Standard 1149.1-1990, entitled Standard Test Access Port and Boundary-Scan Architecture.