ITP700 Debug Port Design Guide

Table 45. Buffered TCK / TMS Implementation Issues

PASS FAIL Don’t’

Care

ISSUE

FBI must be used as the clock input for the buffer.

Is there an individual buffer for each TCK Load?

If there is an extra buffer in the package, FBO should be driven from that

spare buffer. Otherwise, FBO should be connected to an output of the

TCK buffer.

Can TMS be recovered at each scan chain agent given the delay of TCK

through a buffer?

Does the buffer support the drive currents and voltage regions to drive

into the pull-up on the TCK/TMS lines and match the input characteristics

of the scan chain loads?

Are TCK and TMS signals pulled LOW and High respectively through a

bias resistor to set the idle condition of the traces seen by the scan chain

agents?

Table 46. Part 4: Pull-Up / Pull Downs

PASS FAIL N/A Signal Pin

Number

Pull Up / Pull Down

Resistance

Pull Up / Pull Down

Voltage

PWR 22 1.5 kΩ 1% for 2/3rds

recovery.

VTT of BPM[5:0]# and

RESET#

BCLK(p/n) 19, 21 See Processor Datasheet See Processor Datasheet

DBA# 4 150 – 240 Ω VCC

DBR# 6 150 – 240 Ω VCC

FBI 18 220 Ω GND

FBO 17

TCK 16 27 Ω 1% GND

TMS 12 39 Ω 1% VTAP

TDI 10 150 Ω VTAP

TDO 24 75 Ω VTAP

TRST# 14 500 – 680 Ω GND

BPM[5:0]# 13, 11, 9,

7, 5, 3,

See Processor Datasheet VTT

RESET# 15 See Processor Datasheet VTT

BPM5DR# 23 Shorted at debug port BPM[5]#