C509-L_97 Datasheet, PDF (185/290 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C509-L
6.6.2 A/D Converter Registers
This section describes the bits/functions of all registers which are used by the A/D converter.
Special Function Registers ADDATH (Address D9H)
Special Function Registers ADDATL (Address DAH)
Bit No. MSB
7
6
5
4
3
2
D9H
MSB
.9
.8
.7
.6
.5
.4
Reset Value : 00H
Reset Value : 00H
LSB
1
0
.3
.2 ADDATH
DAH
.1
LSB
.0
–
–
–
–
–
– ADDATL
The registers ADDATH and ADDATL contain the 10-bit conversion result in left justified data format.
The most significant bit of the 10-bit conversion result is bit 7 of ADDATH. The least significant bit
of the 10-bit conversion result is bit 6 of ADDATL. To get a 10-bit conversion result, both ADDAT
register must be read. If an 8-bit conversion result is required, only the reading of ADDATH is
necessary. The data remains in ADDAT until it is overwritten by the next converted data. ADDAT
can be read or written under software control. lf the A/D converter of the C509-L is not used, register
ADDATH can be used as an additional general purpose register.
Semiconductor Group
6-107
1997-10-01