MPC8309VMAHFCA Просмотр технического описания (PDF) - Freescale Semiconductor

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MPC8309VMAHFCA

PowerQUICC II Pro Integrated Communications Processor Family Hardware Specifications

Freescale Semiconductor 

Electrical characteristics

2.1.3 Output driver characteristics

The following table provides information on the characteristics of the output driver strengths.

Table 3. Output drive capability

Driver Type

Local bus interface utilities signals

PCI Signal

DDR2 signal

DUART, system control, I2C, SPI, JTAG

GPIO signals

Output Impedance

(Ω)

42

25

18

42

42

Supply Voltage (V)

OVDD = 3.3

GVDD = 1.8

OVDD = 3.3

OVDD = 3.3

2.1.4 Input capacitance specification

The following table describes the input capacitance for the SYS_CLK_IN pin in the MPC8309.

Table 4. Input capacitance specification

Parameter/Condition

Symbol

Min

Input capacitance for all pins except SYS_CLK_IN and

CI

6

QE_CLK_IN

Input capacitance for SYS_CLK_IN and QE_CLK_IN

CICLK_IN

10

Note:

1. The external clock generator should be able to drive 10 pF.

Max

Unit

Note

8

pF

—

—

pF

1

2.2 Power sequencing

The device does not require the core supply voltage (VDD) and I/O supply voltages (GVDD and OVDD) to

be applied in any particular order. Note that during power ramp-up, before the power supplies are stable

and if the I/O voltages are supplied before the core voltage, there might be a period of time that all input

and output pins are actively driven and cause contention and excessive current. In order to avoid actively

driving the I/O pins and to eliminate excessive current draw, apply the core voltage (VDD) before the I/O

voltage (GVDD and OVDD) and assert PORESET before the power supplies fully ramp up. In the case

where the core voltage is applied first, the core voltage supply must rise to 90% of its nominal value before

the I/O supplies reach 0.7 V; see Figure 3. Once both the power supplies (I/O voltage and core voltage) are

stable, wait for a minimum of 32 clock cycles before negating PORESET.

NOTE

There is no specific power down sequence requirement for the device. I/O

voltage supplies (GVDD and OVDD) do not have any ordering requirements

with respect to one another.

MPC8309 PowerQUICC II Pro Integrated Communications Processor Family Hardware Specifications, Rev. 3

10

Freescale Semiconductor

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