// Test and Measurement Connectors

CJTAG Compact JTAG 2-Wire

cJTAG (IEEE 1149.7) reduces JTAG from 4-5 wires to 2 wires (TMSC and TCKC) using a serialized protocol. Saves PCB space on small embedded devices while maintaining full debugging capability.

// Specifications

Standard

IEEE 1149.7 cJTAG

Signals

2 (TMSC and TCKC)

Vs JTAG

4-wire JTAG reduced to 2 wires

Backward Compatible

Supports IEEE 1149.1 4-wire mode

Use Case

Space-constrained embedded devices wearables IoT

Tools

ARM DSTREAM TI XDS110

// Pin Reference Table

Pin	Name	Function	Type
1	VCC	Target supply reference	PWR
2	GND	Ground	GND
3	TMSC	Test mode select combined serial	BUS
4	TCKC	Test clock combined	BUS