36.13.3 ADCCON3 – ADC Control Register 3

This register enables ADC clock selection, enables/disables the digital feature for the shared ADC module and controls the manual (software) sampling and conversion.

Note:

The SAMP bit has the highest priority, and setting this bit keeps the S&H circuit in Sample mode until the bit is cleared. Also, usage of the SAMP bit causes settings of SAMC[9:0] bits (ADCCON2[25:16]) to be ignored.
The SAMP bit only connects Class 2 and Class 3 analog inputs to the shared ADC.
The SAMP bit is not a self-clearing bit and it is the responsibility of application software to first clear this bit and, only after setting the RQCNVRT bit, to start the ADC.
Normally, when the SAMP and RQCNVRT bits are used by software routines, all TRGSRCx[4:0] bits and STRGSRC[4:0] bits must be set to ‘00000’ to disable all external hardware triggers and prevent them from interfering with the software-controlled sampling command signal SAMP and with the software-controlled trigger RQCNVRT.

Name:	ADCCON3
Offset:	0x1420
Reset:	0x00000000
Property:	-


Bit	31	30	29	28	27	26	25	24
	ADCSEL[1:0]		CONCLKDIV[5:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	DIGEN7
Access	R/W
Reset	0


Bit	15	14	13	12	11	10	9	8
	VREFSEL[2:0]			TRGSUSP	UPDIEN	UPDRDY	SAMP	RQCNVRT
Access	R/W	R/W	R/W	R/W	R/W	R/HS/HC	R/W	R/HS/HC
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	GLSWTRG	GSWTRG	ADINSEL[5:0]
Access	R/W	R/W, HC	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 31:30 – ADCSEL[1:0] Analog-to-Digital Clock Source (T_CLK) bits

Value	Description
00	Peripheral Bus Clock (PB1_CLK)
01	FRC Clock
10	REFO3 Clock Output
11	System Clock (SYS_CLK)

Bits 29:24 – CONCLKDIV[5:0] Analog-to-Digital Control Clock (T_Q) Divider bits

Value	Description
111111	64 * T_CLK= T_Q
...	—
000011	4 * T_CLK= T_Q
000010	3 * T_CLK= T_Q
000001	2 * T_CLK= T_Q
000000	T_CLK= T_Q

Bit 23 – DIGEN7 Shared ADC Digital Enable bit

Value	Description
1	ADC is digital enabled
0	ADC is digital disabled

Bits 15:13 – VREFSEL[2:0] Voltage Reference (V_REF) Input Selection bits

Table 36-5.
VREFSEL[2:0]	AD_REF+	AD_REF-
`000`	AV_DD	AV_SS
`001-111`	Reserved

Bit 12 – TRGSUSP Trigger Suspend bit

Value	Description
1	Triggers are blocked from starting a new analog-to-digital conversion, but the ADC module is not disabled
0	Triggers are not blocked

Bit 11 – UPDIEN Update Ready Interrupt Enable bit

Value	Description
1	Interrupt is generated when the UPDRDY bit is set by hardware
0	No interrupt is generated

Bit 10 – UPDRDY ADC Update Ready Status bit

Note: This bit is only active while the TRGSUSP bit is set and there are no more running conversions of any ADC modules.

Value	Description
1	ADC SFRs can be updated
0	ADC SFRs cannot be updated

Bit 9 – SAMP Class 2 and Class 3 Analog Input Sampling Enable bit^(1,2,3,4)

Value	Description
1	The ADC S&H amplifier is sampling
0	The ADC S&H amplifier is holding

Bit 8 – RQCNVRT Individual ADC Input Conversion Request bit

This bit and its associated ADINSEL[5:0] bits enable the user to individually request an ADC of an analog input through software.

Note: This bit is automatically cleared in the next ADC clock cycle.

Value	Description
1	Trigger the conversion of the selected ADC input as specified by the ADINSEL[5:0] bits
0	Do not trigger the conversion

Bit 7 – GLSWTRG Global Level Software Trigger bit

Value	Description
1	Trigger conversion for ADC inputs that have selected the GLSWTRG bit as the trigger signal, either through the associated TRGSRC[4:0] bits in the ADCTRGx registers or through the STRGSRC[4:0] bits in the ADCCON1 register
0	Do not trigger an ADC

Bit 6 – GSWTRG Global Software Trigger bit

This bit is automatically cleared in the next ADC clock cycle.

Value	Description
0	Trigger conversion for ADC inputs that have selected the GSWTRG bit as the trigger signal, either through the associated TRGSRC[4:0] bits in the ADCTRGx registers or through the STRGSRC[4:0] bits in the ADCCON1 register
1	Do not trigger an ADC

Bits 5:0 – ADINSEL[5:0] Analog Input Select bits

These bits select the analog input to be converted when the RQCNVRT bit is set.

Value	Description
111111	Reserved
...	—
001011	VDD33/2(AN11) (Internal)
001010	VDD 1.2V(VDD_1V2(AN10)) (Internal)
001001	ADC Charge-pump 1.2V(CP_1V2(AN9)) (Internal)
001000	BandGap Reference (BG_VREF (AN8)) (Internal)
000111	AN7 is being monitored
...	—
000001	AN1 is being monitored
000000	AN0 is being monitored