ITP700 Debug Port Design Guide

R
12 ITP700 Debug Port Design Guide
• Hot-plug support for the debug port adapter (DPA) into a target system.
• Supports arbitration with a local TAP Master (e.g. manufacturing test chain) through a simple
handshake.
1.2 Recommended Signal Terminations
Table 1. Recommended Debug Port Signal Terminations
Signal Termination Value Termination
Voltage
Termination
Location
Notes
PWR 1.5 kΩ 1% VTERM of BPM[5:0]#
and RESET#
Within 1 ns of debug
port
1
BCLK(p/n) 2
DBA# 150 – 240 Ω 5% VCC of target system
recovery circuit.
Within 1 ns of debug
port
3
DBR# 150 – 240 Ωs 5% VCC of target system
recovery circuit
Within 1 ns of debug
port
FBI 220 Ω 5% GND Within 200 ps of the
receiver
4
FBO Connect to TCK pin at the closest
BPM[5:0]# bus load device
NA NA
TCK 27 Ω 1% GND Within 200 ps of the
debug port
TMS 39 Ω 1 % VTAP Within 200 ps of the
debug port
TDI 150 Ω 5% VTAP Within 300 ps of the
receiver
5
TDO 75 Ω 5% VTAP Within 300 ps of the
debug port
5
TRST# 500 – 680 Ω 5% GND
BPM[5:0]# Characteristic impedance of the
transmission line 5%
VTERM 2
RESET# Characteristic impedance of the
transmission line 5%
VTERM 2
BPM5DR# Connect to BPM[5]# at the debug
port
NA NA
NOTES:
1. The target system resistor connected between VTERM and the PWR pin is part of a voltage division
circuit (see below). The voltage derived from the voltage divider is used as a reference for recovery of
the BPM[5:0]# and RESET# signals on the ITP. The recovery point of the BPM[5:0]# and RESET#
signals can be modified by scaling the target system resistor. The standard 1.5 K 1% target system
resistor will result in a recovery point of 2/3rds of VTERM.
2. Resistance, voltage, and termination location are defined in the Platform Design Guide documentation.
3. Only required if DBA# is used with any target system circuitry. This signal may be left unconnected if
unused.
4. Only required if FBI is used to source a buffer for JTAG TCK. This signal may be left unconnected if
unused.
5. A termination resistor must be located at the receiver of each scan chain agent