Datasheet
MCP3901
DS22192D-page 48 © 2011 Microchip Technology Inc.
7.6 Configuration Registers
The Configuration registers contain settings for the
internal clock prescaler, the oversampling ratio, the
Channel 0 and Channel 1 width settings of 16 or
24 bits, the modulator output control settings, the state
of the channel Resets and shutdowns, the dithering
algorithm control (for Idle tones suppression), and the
control bits for the external V
REF and external CLK.
REGISTER 7-6: CONFIGURATION REGISTERS:
CONFIG1: ADDRESS 0x0A, CONFIG2: ADDRESS 0x0B
R/W-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0
PRESCALE
<1>
PRESCALE
<0>
OSR<1> OSR<0> WIDTH
_CH1
WIDTH
_CH0
MODOUT
_CH1
MODOUT
_CH0
bit 15 bit 8
R/W-0 R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-0 R/W-0
RESET
_CH1
RESET
_CH0
SHUTDOWN
_CH1
SHUTDOWN
_CH0
DITHER
_CH1
DITHER
_CH0
VREFEXT CLKEXT
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 15-14 PRESCALE<1:0>: Internal Master Clock (AMCLK) Prescaler Value bits
11 = AMCLK = MCLK/8
10 = AMCLK = MCLK/4
01 = AMCLK = MCLK/2
00 = AMCLK = MCLK (default)
bit 13-12 OSR<1:0>: Oversampling Ratio for Delta-Sigma A/D Conversion bits (all channels, DMCLK/DRCLK)
11 = 256
10 = 128
01 = 64 (default)
00 = 32
bit 11-10 WIDTH_CH<1:0>: ADC Channel Output Data Word Width bits
1 = 24-bit mode
0 = 16-bit mode (default)
bit 9-8 MODOUT_CH<1:0>: Modulator Output Setting for MDAT Pins bits
11 = Both CH0 and CH1 modulator outputs present on MDAT1 and MDAT0 pins
10 = CH1 ADC modulator output present on MDAT1 pin
01 = CH0 ADC modulator output present on MDAT0 pin
00 = No modulator output is enabled (default)
bit 7-6 RESET_CH<1:0>: Reset Mode Setting for ADCs bits
11 = Both CH0 and CH1 ADC are in Reset mode
10 = CH1 ADC in Reset mode
01 = CH0 ADC in Reset mode
00 = Neither Channel in Reset mode (default)
bit 5-4 SHUTDOWN_CH<1:0>: Shutdown Mode Setting for ADCs bits
11 = Both CH0 and CH1 ADC are in Shutdown
10 = CH1ADC is in shutdown
01 = CH0 ADC is in shutdown
00 = Neither Channel is in shutdown (default)
bit 3-2 DITHER_CH<1:0>: Control for Dithering Circuit bits
11 = Both CH0 and CH1 ADC have dithering circuit applied (default)
10 = Only CH1 ADC has dithering circuit applied
01 = Only CH0 ADC has dithering circuit applied
00 = Neither Channel has dithering circuit applied