DSP56311D View Datasheet(PDF) - Motorola => Freescale

Part Name

Description

Manufacturer

DSP56311D

24-Bit Digital Signal Processor

Motorola => Freescale 

AC Electrical Characteristics

2.5 AC Electrical Characteristics

The timing waveforms shown in the AC electrical characteristics section are tested with a VIL maximum

of 0.3 V and a VIH minimum of 2.4 V for all pins except EXTAL, which is tested using the input levels

shown in Note 6 of Table 2-2. AC timing specifications, which are referenced to a device input signal,

are measured in production with respect to the 50 percent point of the respective input signal’s transition.

DSP56311 output levels are measured with the production test machine VOL and VOH reference levels set

at 0.4 V and 2.4 V, respectively.

Note: Although the minimum value for the frequency of EXTAL is 0 MHz, the device AC test

conditions are 15 MHz and rated speed.

2.5.1 Internal Clocks

Table 2-4. Internal Clocks

Expression1, 2

Characteristics

Symbol

Min

Typ

Max

Internal operation frequency with

f

—

(Ef × MF)/

—

PLL enabled

(PDF × DF)

Internal operation frequency with

f

—

Ef/2

—

PLL disabled

Internal clock high period

• With PLL disabled

TH

—

ETC

—

• With PLL enabled and MF ≤ 4

0.49 × ETC ×

—

0.51 × ETC ×

PDF × DF/MF

PDF × DF/MF

• With PLL enabled and MF > 4

0.47 × ETC ×

—

0.53 × ETC ×

PDF × DF/MF

PDF × DF/MF

Internal clock low period

• With PLL disabled

• With PLL enabled and

MF ≤ 4

• With PLL enabled and

MF > 4

TL

—

ETC

—

0.49 × ETC ×

—

0.51 × ETC ×

PDF × DF/MF

PDF × DF/MF

0.47 × ETC ×

—

0.53 × ETC ×

PDF × DF/MF

PDF × DF/MF

Internal clock cycle time with PLL

TC

—

ETC × PDF ×

—

enabled

DF/MF

Internal clock cycle time with PLL

TC

—

2 × ETC

—

disabled

Instruction cycle time

ICYC

—

TC

—

Notes: 1. DF = Division Factor; Ef = External frequency; ETC = External clock cycle; MF = Multiplication Factor;

PDF = Predivision Factor; TC = internal clock cycle.

2. See the PLL and Clock Generation section in the DSP56300 Family Manual for a details on the PLL.

2-4

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