Itp700Flex Debug Port Signals - Intel 855GME Design Manual

®
Intel 855GME Chipset and Intel
Figure 36. ITP700FLEX Debug Port Signals
ITPCLK[1:0]
CPUCLK[1:0]
GMCHCLK[1:0]
CK409
L7
BCLK[1:0]
®
Intel
855GME
Chipset
CPURESET#
1. Route the TDI signal between the ITP700FLEX connector and the Intel Pentium M/Celeron M
processor. A 150- Ω ±5 percent pull-up to VCCP (1.05 V) should be placed within ± 300 ps of
the TDI pin.
2. Route the TMS signal between ITP700FLEX connector and the Intel Pentium M/Celeron M
processor. A 39.2- Ω ±1 percent pull-up to VCCP should be placed within ± 200 ps of the
ITP700FLEX connector pin.
3. Route the TRST# signal between ITP700FLEX connector and the Intel Pentium M/Celeron M
processor. A 510 Ω to 680 Ω ± 5 percent pull-down to ground should be placed on TRST#.
Placement of the pull-down resistor is not critical. Avoid having any trace stub from the
TRST# signal line to the termination resistor.
4. Route the TCK signal from the ITP700FLEX connector's TCK pin to the Intel Pentium
M/Celeron M processor's TCK pin and then fork back from the Pentium M processor TCK pin
and route back to ITP700FLEX connector's FBO pin. A 27.4 Ω ± 1 percent pull-down to
ground should be placed within ± 200 ps of the ITP700FLEX connector pin.
5. Route the TDO signal from the Intel Pentium M/Celeron M processor to a 54.9 Ω ± 1 percent
pull-up resistor to VCCP that should be placed close to ITP700FLEX connector's TDO pin.
Then insert a 22.6 Ω ± 1 percent series resistor to connect the 54.9 Ω pull-up and 'TDOITP'
net (see
The Intel Pentium M/Celeron M processor drives the BPM[4:0]# signals to the ITP700FLEX at a
100 MHz clock rate. Route the BPM[4:0]# as a Zo=55 Ω point-to-point transmission line
connection between the processor and the ITP700FLEX connector. Connect the ITP700FLEX
78
®
6300ESB ICH Embedded Platform Design Guide
L6
TDI
BCLK[1:0]
TMS
TRST#
®
Intel
®
Pentium M
Processor
TC
K
TDO
BPM[3:0]#
PRDY#
PREQ#
RESET#
L5
Figure 36). Limit the L1 segment length of the TDOITP net to less than 1.0 inch.
L8
1.05 v
150
5%
TDI
TMS
TRST#
680
5%
FBO
TCK
54.9
TDO
L2
BPM[3:0]#
BPM[4]#
BPM[5]#
RESET#
L3
BCLKp
BCLKn
1.05 v
39.2
1%
TDI
TDI
TMS
TMS
TRST#
TRST#
1.05 v
VTT
VTT
0.1u
F
VTAP
FBO
FBO
TCK
TCK
27.4
1.05 v
1%
L1
22.6
1%
TDOITP
TDO
BPM[5:0]#
VCC VCC
240 240
1.05 v 5% 5%
DBR#
54.9
DBA#
1%
RESETITP#
RESET#
22.6
L4
1%
DBR
DBA #
#