MPC8377E datasheet(10/127 Pages) FREESCALE

10 / 127 page

MPC8377E PowerQUICC II Pro Processor Hardware Specifications, Rev. 8

Freescale Semiconductor

2.1.3

chip

Output Driver Characteristics

This table provides information on the characteristics of the output driver strengths. The values are

preliminary estimates.

2.2

Power Sequencing

The device requires its power rails to be applied in a specific sequence in order to ensure proper device

operation. During the power ramp up, before the power supplies are stable and if the I/O voltages are

supplied before the core voltage, there may be a period of time that all input and output pins will actively

be driven and cause contention and excessive current. To avoid actively driving the I/O pins and to

eliminate excessive current draw, apply the core voltages (VDD and AVDD) before the I/O voltages and

assert PORESET before the power supplies fully ramp up. VDD and AVDD must reach 90% of their

nominal value before GVDD, LVDD, and OVDD reach 10% of their value, see the following figure. I/O

Table 4. Output Drive Capability

Driver Type1

Output Impedance (

Ω)

Supply Voltage

Local bus interface utilities signals

LBVDD = 2.5 V, 3.3 V

LBVDD = 1.8 V

PCI signals

OVDD = 3.3 V

DDR1 signal

GVDD = 2.5 V

DDR2 signal

GVDD = 1.8 V

eTSEC 10/100/1000 signals

LVDD = 2.5 V, 3.3 V

DUART, system control, I2C, JTAG, SPI, and USB

OVDD = 3.3 V

GPIO signals

OVDD = 3.3 V

Note:

1. Specialized SerDes output capabilities are described in the relevant sections of these specifications (such as PCI Express

and SATA)

MPC8377E Datasheet(PDF) 10 Page - Freescale Semiconductor, Inc