
Data Sheet
ADuC7019/20/21/22/24/25/26/27/28/29
Rev. F | Page 47 of 104
Table 18. ADCCON MMR Bit Designations
Bit
Value
Description
15:13
Reserved.
12:10
ADC clock speed.
000
fADC/1. This divider is provided to obtain
1 MSPS ADC with an external clock <41.78 MHz.
001
fADC/2 (default value).
010
fADC/4.
011
fADC/8.
100
fADC/16.
101
fADC/32.
9:8
ADC acquisition time.
00
Two clocks.
01
Four clocks.
10
Eight clocks (default value).
11
16 clocks.
7
Enable start conversion.
Set by the user to start any type of conversion
command. Cleared by the user to disable a
start conversion (clearing this bit does not
stop the ADC when continuously converting).
6
Reserved.
5
ADC power control.
Set by the user to place the ADC in normal
mode (the ADC must be powered up for at least
5 μs before it converts correctly). Cleared by the
user to place the ADC in power-down mode.
4:3
Conversion mode.
00
Single-ended mode.
01
Differential mode.
10
Pseudo differential mode.
11
Reserved.
2:0
Conversion type.
000
Enable CONVSTART pin as a conversion input.
001
Enable Timer1 as a conversion input.
010
Enable Timer0 as a conversion input.
011
Single software conversion. Sets to 000 after
conversion (note that Bit 7 of ADCCON MMR
should be cleared after starting a single
software conversion to avoid further
conversions triggered by the CONVSTART pin).
100
Continuous software conversion.
101
PLA conversion.
Other
Reserved.
Table 19. ADCCP Register
Name
Address
Default Value
Access
ADCCP
0xFFFF0504
0x00
R/W
ADCCP is an ADC positive channel selection register. This
Table 20. ADCCP1 MMR Bit Designation Bit
Value
Description
7:5
Reserved.
4:0
Positive channel selection bits.
00000
ADC0.
00001
ADC1.
00010
ADC2.
00011
ADC3.
00100
ADC4.
00101
ADC5.
00110
ADC6.
00111
ADC7.
01000
ADC8.
01001
ADC9.
01010
ADC10.
01011
ADC11.
01100
DAC0/ADC12.
01101
DAC1/ADC13.
01110
DAC2/ADC14.
01111
DAC3/ADC15.
10000
Temperature sensor.
10001
AGND (self-diagnostic feature).
10010
Internal reference (self-diagnostic feature).
10011
AVDD/2.
Others
Reserved.
1
ADC and DAC channel availability depends on the part model. S
ee OrderingTable 21. ADCCN Register
Name
Address
Default Value
Access
ADCCN
0xFFFF0508
0x01
R/W
ADCCN is an ADC negative channel selection register. This