Pentium
III Processor at 450 MHz, 500 MHz, 533B MHz, 550 MHz, 600/600B MHz
Datasheet
25
NOTES:
1. Unless otherwise noted, all specifications in this table apply to Pentium
III processor frequencies.
2. VIH and VOH for the Pentium III processor may experience excursions of up to 200 mV above VTT for a single system bus
clock. However, input signal drivers must comply with the signal quality specifications in Section 3.0.
3. Minimum and maximum VTT are given in Table 10.
4. Parameter correlated to measure into a 25
resistor terminated to 1.5 V.
5. IOH for the Pentium III processor may experience excursions of up to a 12 mA for a single bus clock.
6. (0
≤ VIN ≤ 2.0 V +5%).
7. (0
≤ VOUT ≤ 2.0 V +5%).
8. Refer to the Pentium III I/O Buffer Models for I/V characteristics.
NOTES:
1. Unless otherwise noted, all specifications in this table apply to all Pentium
III processor frequencies.
2. Parameter measured at 14 mA (for use with TTL inputs).
3. (0
≤ VIN ≤ 2.5 V +5%).
4. (0
≤ VOUT ≤ 2.5 V +5%).
2.12
AGTL+ System Bus Specifications
It is recommended that the AGTL+ bus be routed in a daisy-chain fashion with termination
resistors to V
TT at each end of the signal trace. These termination resistors are placed electrically
between the ends of the signal traces and the V
TT voltage supply and generally are chosen to
approximate the substrate impedance. The valid high and low levels are determined by the input
buffers using a reference voltage called V
REF.
Table 10 lists the nominal specification for the AGTL+ termination voltage (V
TT). The AGTL+
reference voltage (V
REF) is generated on the processor substrate for the processor core, but should
be set to 2/3 V
TT for other AGTL+ logic using a voltage divider on the baseboard. It is important
that the baseboard impedance be specified and held to a ±15% tolerance, and that the intrinsic trace
Table 8.
AGTL+ Signal Groups DC Specifications 1, 4, 5
Symbol
Parameter
Min
Max
Unit
Notes
VIL
Input Low Voltage
–0.3
0.82
V
VIH
Input High Voltage
1.22
VTT
V2, 3
Ron
Buffer On Resistance
16.67
8
IL
Leakage Current
±100
A
6
ILO
Output Leakage Current
±15
A
7
Table 9.
Non-AGTL+ Signal Group DC Specifications 1
Symbol
Parameter
Min
Max
Unit
Notes
VIL
Input Low Voltage
–0.3
0.5
V
VIH
Input High Voltage
1.7
2.625
V
2.5 V +5% maximum
VOL
Output Low Voltage
0.4
V
2
VOH
Output High Voltage
N/A
2.625
V
All outputs are
open-drain
IOL
Output Low Current
14
mA
ILI
Input Leakage Current
±100
A
3
ILO
Output Leakage Current
±15
A
4