XJXDP

Overview
Benefits
Features

XJXDP is an adaptor that complements an XJLink JTAG controller by providing a very low impedance drive capability, down to 25 Ohms or less. The small form factor board can be directly mounted onto an Intel® eXtended Debug Port (XDP) for minimum wire lengths and maximum performance, or connected via a 2 mm pitch 20-way ribbon cable.

Key Benefits

Provides signal matching to improve JTAG performance

High efficiency tracking power supply

Supports non-XDP applications

Features

Direct connection to XDP port
Flex cable option for tight access situations
High signal integrity
TCK clock frequencies up to 100 MHz
Flexible power supply voltage: 5 V to 15 V
VTT tracking internal power supply
Supports I/O voltages from 0.6 V to 3.3 V
8 channels configured as 3 uplink, 5 downlink
Plugs directly into XJLink2 controller
Completely transparent to XJTAG software

Low voltage, low impedence

Some devices, notably Intel processors, use low voltage signalling with low value termination resistors typically in the range 0.8 V to 1.2 V and 25-50 Ohms. The XJXDP uses purpose designed low impedance drive circuits to get the highest noise margins and fastest JTAG clocking speeds.

Precision line receivers

Precision, ultra-high speed comparators, with resistor-programmable hysteresis are used as uplink receivers for the highest receiver noise margin and speed performance.

Flexible

In addition to the XDP port connector, a standard 2mm pitch header is provided to allow ribbon cable connection for non-XDP applications. The XDP connector can also mate with a flex XDP-to-XDP extender cable.

Tracking power supply

The XJXDP uses a high efficiency tracking power supply to track the UUT’s VTT output (voltage reference), enabling it to drive low impedance downlink signals with minimal loading of the UUT. The XJXDP can be powered directly if you are using an XJLink2-series controller, otherwise can use an external power supply.

Controlled rise/fall times

Low impedance downlink drivers can produce extremely fast edges that can cause undesirable overshoot, leading to loss of signal integrity and reliability. The XJXDP signal drivers moderate rise/fall times to enable the highest clock speeds, with the greatest reliability and highest test throughput.