C517A_99 Datasheet, PDF (162/218 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C517A
Special Function Registers ADCON0 (Address D8H)
Special Function Registers ADCON1 (Address DCH)
Reset Value : 00H
Reset Value : 0XXX0000B
Bit No. MSB
7
D8H BD
6
5
4
CLK ADEX BSY
3
ADM
2
MX2
1
MX1
LSB
0
MX0
ADCON0
DCH ADCL –
–
– MX3 _{MX2 MX1 MX0 ADCON1}
The shaded bits are not used for A/D converter control.
Bit
–
ADEX
BSY
ADM
MX3 - MX0
Function
Reserved bits for future use
Internal / external start of converrsion
When set, the external start of an A/D conversion by a falling edge at pin
P6.0 / ADST is enabled.
Busy flag
This flag indicates whether a conversion is in progress (BSY = 1). The flag
is cleared by hardware when the conversion is finished.
A/D conversion mode
When set, a continuous A/D conversion is selected. If cleared, the
converter stops after one A/D conversion.
A/D converter input channel select bits
Bits MX3-0 can be written or read either in ADCON0 or ADCON1. The
channel selection done by writing to ADCON 1(0) overwrites the selection
in ADCON 0(1) when ADCON 1(0) is written after ADCON 0(1).
The analog inputs are selected according the following table :
MX3 MX2 MX1 MX0
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
Selected Analog Input
P7.0 / AN0
P7.1 / AN1
P7.2 / AN2
P7.3 / AN3
P7.2 / AN4
P7.3 / AN5
P7.4 / AN6
P7.5 / AN7
P8.0 / AN8
P8.1 / AN9
P8.2 / AN10
P8.3 / AN11
Semiconductor Group
6-96