Table of Contents
Advertisement
7 How to configure the SSCG Unit
7.1 SSCG Unit Default Values
The SSCG unit has the following default settings:
SSCG_PERIOD = 35 kHz. Note the recommended value for use is 20 kHz!
SSCG_PERIOD_JITTER = 0x90. Note the recommended value for use is approx. 0x70!
SSCG_CTRL.SSCG_TYPE = 0x11 (Centerspread)
Modulation Peak = +/- 1.56%
SSCG_FOFFSET = 0x0
SSCG_IEN = 0
7.2 Configuring the SSCG Registers
Using the Hardware Manual, select one of the tables which list the settings of the various SSCG
registers.
Example
An operating frequency of 20 kHz is required for the SSCG and the PLL clock is running at 666 MHz.
The relevant table is shown below.
SSCG_PEAK_FREQUENCY = 0
SSCG_FOFFSET = 0x0
SSCG_TYPE
SSCG_PERIOD
3
0x82
Centerspread
2
Upspread
0x82
(unused)
1
0x82
Downspread
For a centerspread type and a Modulation Peak of 1.56%, use the following settings:
SSCG_PERIOD_JITTER = 0x68 (10 %) = 1101000 (bin)
Modulation Peak = +/- 1.56%
SSCG_PERIOD = 0x82 = 10000010 (bin)
SSCG_FSTEP = 0x1 C94F = 11100100101001111 (bin)
Please take note of the limitations listed in the Hardware Manual.
Version 1.30
SSCG_PERIOD_JITTER
0x68
0x68
0x68
14
Modulation Peak %
0.50
1.00
1.56
0.50
1.00
1.56
0.50
1.00
1.56
SSCG_FSTEP
0x9292
0x1 2525
0x1 C94F
0x4949
0x9292
0xE4A7
0x4949
0x9292
0xE4A7
Advertisement
Table of Contents
