Intel G470 BX80623G470 Manual Do Utilizador
Códigos do produto
BX80623G470
28
Intel
®
Celeron
®
Processor on 0.13 Micron Process in the 478-Pin Package
Datasheet
Electrical Specifications
2.12
AGTL+ System Bus Specifications
. Termination resistors are not required for most AGTL+ signals because termination
resistors are integrated into the processor silicon.
Valid high and low levels are determined by the input buffers which compare a signal’s voltage
with a reference voltage called GTLREF (known as V
with a reference voltage called GTLREF (known as V
REF
in previous documentation).
lists the GTLREF specifications. The AGTL+ reference voltage (GTLREF) should be
generated on the system board using high precision voltage divider circuits. It is important that the
system board impedance be held to the specified tolerance, and that the intrinsic trace capacitance
for the AGTL+ signal group traces is known and is well-controlled. For more details on platform
design, see the appropriate Platform Design Guide listed
system board impedance be held to the specified tolerance, and that the intrinsic trace capacitance
for the AGTL+ signal group traces is known and is well-controlled. For more details on platform
design, see the appropriate Platform Design Guide listed
in
Table 15. AGTL+ Bus Voltage Definitions
Symbol
Parameter
Min
Typ
Max
Units
Notes
1
NOTES:
1.
Unless otherwise noted, all specifications in this table apply to all processor frequencies.
GTLREF
Bus Reference Voltage
2/3 VCC
– 2%
2/3 VCC
2/3 VCC
+ 2%
V
2,
3,
4
2.
The tolerances for this specification have been stated generically to enable the system designer to calculate
the minimum and maximum values across the range of VCC.
the minimum and maximum values across the range of VCC.
3.
GTLREF should be generated from VCC by a voltage divider of 1% tolerance resistors, or 1% tolerance
matched resistors. Refer to the appropriate Platform Design Guide listed in
matched resistors. Refer to the appropriate Platform Design Guide listed in
for implementation details.
4.
The VCC referred to in these specifications is the instantaneous VCC.
R
TT
Termination Resistance
45
50
55
Ω
5
5.
R
TT
is the on-die termination resistance measured at VOL of the AGTL+ output driver. Refer to processor
I/O buffer models for I/V characteristics.
COMP[1:0]
COMP Resistance
50.49
51
51.51
Ω
6
6.
COMP resistance must be provided on the system board with 1% tolerance resistors. See the appropriate
Platform Design Guide for implementation details.
Platform Design Guide for implementation details.