IXP45X datasheet(147/148 Pages) INTEL

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Intel® IXP45X and Intel® IXP46X Product Line of Network Processors

August 2006

Datasheet

Document Number: 306261-004US

147

Datasheet—Intel® IXP45X and Intel® IXP46X Product Line of Network Processors

5.7

Power Sequence

The 3.3-V I/O voltage (VCCP) and the 2.5-V I/O voltage (VCCM) must be powered up at

least 1 µs before the processor voltage (VCC). The IXP45X/IXP46X network processors

voltage (VCC) must never become stable prior to the 3.3-V I/O voltage (VCCP) or the

2.5-V I/O voltage (VCCM).

Sequencing between VCCP and VCCM can occur in any order with respect to one another.

TIO_PHASE can be:

•VCCP prior to VCCM

•VCCM prior to VCCP

•VCCP simultaneously to VCCM

The VCCOSC, VCCPLL1, VCCPLL2, and VCCPLL3 voltages follow the VCC power-up pattern.

The VCCOSCP follows the VCCP power-up pattern.

The value for TPOWER_UP must be at least 1 µs after the later of VCCP and VCCM reaching

stable power. The TPOWER_UP timing parameter is measured between the later of the I/

O power rails (VCCP at 3.3 V or VCCM at 2.5 V) and VCC at 1.3 V.

5.8

Power Dissipation

The Intel® IXP45X and Intel® IXP46X Product Line of Network Processors were tested

assuming a typical worst case networking application under a tester environment. The

following power assessments in Table 82 assume this typical worst case networking

application using the interface activity factors listed in Table 83. The actual power may

vary if interface activity factors are different from Table 83. If applications do not

require use of certain peripherals or if interfaces operate at lower activity factors, then

the power required by the part may be significantly less than the numbers stated in

Table 82.

Figure 50.

Power-up Sequence Timing

TIME

CCP

CCM

IO_PHASE TPOWER_UP

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