Silicon Laboratories Si446 Series, Руководство пользователя

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AN625
Rev. 0.1 91
3.5.88. MODEM_DSM_CTRL
 Summary: DSM control
 Purpose:

Delta Sigma Modulator control
 Property: 0x2002
 Default: 0x07
 Fields:

dsmclk_sel - default:0 DSM clock source selection.
0 = DSM clock comes from 30MHz PLL feedback clock.
1 = DSM clock comes from 30MHz crystal clock.

dsm_mode - default:0
0 = MASH 1-1-1 DSM will be selected.
1 = A single loop DSM will be selected.

dsmdt_en - default:0
0 = DSM dithering is disabled.
1 = DSM dithering is enabled.

dsmdttp - default:0 Dithering type
0 = +1/0 is added to DSM input LSB.
1 = +1/-1 is added to DSM input LSB.

dsm_rst - default:0
0 = DSM reset is not active.
1 = DSM will be in reset state until it is clear.

dsm_lsb - default:1 If set, DSM LSB input will be high all times.

dsm_order[1:0] - default:0x3 DSM Mode
0 = 0 order, with 0 output continuously.
1 = 1st order, on noise shaping.
2 = 2nd order, MASH 1-1.
3 = 3rd order, MASH 1-1-1.
 Register View
MODEM_DSM_CTRL
7 6 5 4 3 2 1 0
DSMCLK_SEL DSM_MODE DSMDT_EN DSMDTTP DSM_RST DSM_LSB DSM_ORDER[1:0]
0 0 0 0 0 1 0x3