TMS320VC5416 datasheet(56/98 Pages) TI1

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5.3.3 Internal Oscillator With External Crystal

1C2

) C2)

X2/CLKIN

Crystal

TMS320VC5416

Fixed-Point Digital Signal Processor

SPRS095P – MARCH 1999 – REVISED OCTOBER 2008

www.ti.com

The internal oscillator is enabled by selecting the appropriate clock mode at reset (this is

device-dependent; see Section 3.10) and connecting a crystal or ceramic resonator across X1 and

X2/CLKIN. The CPU clock frequency is one-half, one-fourth, or a multiple of the oscillator frequency. The

multiply ratio is determined by the bit settings in the CLKMD register.

The crystal should be in fundamental-mode operation, and parallel resonant, with an effective series

resistance of 30

Ω maximum and power dissipation of 1 mW. The connection of the required circuit,

consisting of the crystal and two load capacitors, is shown in Figure 5-2. The load capacitors, C1 and C2,

should be chosen such that the equation below is satisfied. CL (recommended value of 10 pF) in the

equation is the load specified for the crystal.

Table 5-1. Input Clock Frequency Characteristics

MIN

MAX

Unit

Input clock frequency

10(1)

20(2)

MHz

(1)

This device utilizes a fully static design and therefore can operate with tc(CI) approaching ∞. The device is characterized at frequencies

approaching 0 Hz

(2)

It is recommended that the PLL multiply by N clocking option be used for maximum frequency operation.

Figure 5-2. Internal Divide-By-Two Clock Option With External Crystal

Electrical Specifications

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TMS320VC5416 Datasheet(PDF) 56 Page - Texas Instruments