Flying Lead Connectors

When you layout the printed circuit board for use with JTAG in-system programming and testing, a few adjustments will make the process of connecting and downloading easier.

Provide pins on your printed circuit board for VCC, GND, TCK, TDO, TDI and TMS.
These pins must be standard 0.025” square male pins that have dedicated traces to the target system control pins. You connect to these pins with the flying lead connector.
Place pins on board so that flying leads can reach them. The length of our flying leads is six inches. While pins may be a couple inches apart, do not have any two JTAG pins more than six inches apart.
Keep header pins on your board a minimum of 0.10” apart.

Table 2_3 Parallel Cable Connections and Definitions

Name	Function	Connections
VCC	Power - Supplies V_CC (5 V, 10 mA, typically) to the cable.	To target system V_CC
GND	Ground - Supplies ground reference to the cable.	To target system ground
TCK	Test Clock - this clock drives the test logic for all devices on boundary-scan chain.	Connect to system TCK pin.
TDO	Read Data - Read back data from the target system is read at this pin.	Connect to system TDO pin.
TDI	Test Data In - this signal is used to transmit serial test instructions and data.	Connect to system TDI pin.
TMS	Test Mode Select - this signal is decoded by the TAP controller to control test operations.	Connect to system TMS pin.

Flying Lead Connectors

Table 2_3 Parallel Cable Connections and Definitions

Figure 2.7 JTAG Cable and Leads (parallel cable shown)