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5 The SSCG unit in MB86R02 'Jade-D'
The SSCG unit plays an essential role in the MB86R02 'Jade-D' GDC providing the 'heartbeat' of the
digital units in the device. Whereas the internal PLL provides a non-modulated clock to the internal
units via the Clock/Reset Distribution unit, the SSCG can be configured and then activated to provide a
modulated clock signal.
5.1 Operating Frequency Ranges
Much the same as in an automobile, the SSCG unit can be operated in one of two 'gears', i.e. one of
the following input frequency ranges (delivered by the internal PLL):
400 MHz – 550 MHz
550 MHz – 700 MHz (Default)
5.2 Modulation Parameters
5.2.1
Modulation Period
The SSCG unit can produce a modulated clock signal whose period (or wavelength) is variable in the
range of:
1/1,048,320 to 1/256
of the (input) PLL clock.
Example
With a PLL input clock of 666 MHz, this means the period of the modulated signal can be theoretically
in a range between 636 Hz (666 MHz * [1/1,048,320]) and 2.6 MHz (666 MHz * [1/256])
Recommended period range 15 kHz - 35 kHz
( 0x4A <= SSCG_PERIOD <= 0xAD)
Recommended setting for 20 kHz: SSCG_PERIOD <= 0x82
Version 1.30
Figure 2 SSCG Location
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