Not Recommended for New Designs

CDC706

SCAS829B – SEPTEMBER 2006 – REVISED FEBRUARY 2008...................................................................................................................................... www.ti.com

Byte 25, Bit [6:4]: SSC Modulation Amount (1)

SSC2

SSC1

SSC0

Function

Default (2)

0

0

0

SSC Modulation Amount 0% = SSC bypass for PLL(3)

Yes

0

0

1

SSC Modulation Amount ±0.1% (center spread)

0

1

0

SSC Modulation Amount ±0.25% (center spread)

0

1

1

SSC Modulation Amount ±0.4% (center spread)

1

0

0

SSC Modulation Amount 1% (down spread)

1

0

1

SSC Modulation Amount 1.5% (down spread)

1

1

0

SSC Modulation Amount 2% (down spread)

1

1

1

SSC Modulation Amount 3% (down spread)

(1)

The PLL has to be bypassed (turned off) when changing SSC Modulation Amount on-the-fly. This can be done by following

programming sequence: bypass PLL2 (Byte 3, Bit 6 = 1); write new Modulation Amount (Byte 25); re-activate PLL2 (Byte 3, Bit 6 = 0).

(2)

Unless customer specific setting.

(3)

If SSC bypass is selected, SSC circuitry of PLL2 is powered-down and the SSC output is reset to logic low. The non-SSC output of

PLL2 is not affected by this mode and can still be used.

Byte 26, Bit [6:0]: Byte Count (1)

BC6

BC5

BC4

BC3

BC2

BC1

BC0

No. of Bytes

Default (2)

0

0

0

0

0

0

0

Not allowed

0

0

0

0

0

0

1

1

0

0

0

0

0

1

0

2

0

0

0

0

0

1

1

3

•

•

•

0

0

1

1

0

1

1

27

Yes

•

•

•

1

1

1

1

1

0

1

125

1

1

1

1

1

1

0

126

1

1

1

1

1

1

1

127

(1)

Defines the number of Bytes, which will be sent from this device at the next Block Read protocol.

(2)

Unless customer specific setting.

20

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