Texas Instruments 3138 155 232931 manual FSTST0 0x27 Frequency Synthesizer Test Register

CC2420

FSTST0 (0x27) - Frequency Synthesizer Test Register 0

Bit	Field Name	Reset	R/W
15:12	-	0	W0
11	VCO_ARRAY_SETTLE_LONG	0	R/W
10	VCO_ARRAY_OE	0	R/W
9:5	VCO_ARRAY_O[4:0]	16	R/W
4:0	VCO_ARRAY_RES[4:0]	16	R

Description

Reserved, write as 0

When '1' this control bit doubles the time allowed for VCO settling during VCO calibration.

VCO array manual override enable.

VCO array override value.

The VCO array result holds the register content of the most recent calibration.

FSTST1 (0x28) - Frequency Synthesizer Test Register 1

Bit	Field Name	Reset	R/W
15	VCO_TX_NOCAL	0	R/W
14	VCO_ARRAY_CAL_LONG	1	R/W
13:10	VCO_CURRENT_REF[3:0]	4	R/W
9:4	VCO_CURRENT_K[5:0]	0	R/W
3	VC_DAC_EN	0	R/W
2:0	VC_DAC_VAL[2:0]	2	R/W

Description

0 : VCO calibration is always performed when going to RX or when going to TX.

1 : VCO calibration is only performed when going to RX or when using the STXCAL command strobe

When ‘1’ this control bit doubles the time allowed for VCO frequency measurements during VCO calibration.

0 : PLL Calibration time is 37 us

1 : PLL Calibration time is 57 us

The value of the reference current calibrated against during VCO calibration.

VCO current calibration constant. (Current B override value when FSTST2.VCO_CURRENT_OE=1.)

Controls the source of the VCO VC node in normal operation (TOPTST.VC_IN_TEST_EN=0):

0:Loop filter (closed loop PLL)

1:VC DAC (open loop PLL)

VC DAC output value

FSTST2 (0x29) - Frequency Synthesizer Test Register 2

Bit	Field Name	Reset	R/W
15	-	0	W0
14:13	VCO_CURCAL_SPEED[1:0]	0	R/W

12	VCO_CURRENT_OE	0	R/W
11:6	VCO_CURRENT_O[5:0]	24	R/W
5:0	VCO_CURRENT_RES[5:0]	32	R

Description

Reserved, write as 0.

VCO current calibration speed:

0:Normal

1:Double speed

2:Half speed

3:Undefined.

VCO current manual override enable.

VCO current override value (current A).

The VCO current result holds the register content of the most recent calibration.

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