SAB80515 Datasheet, PDF (77/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

On-Chip Peripheral Components
If DAPR (.3-.0) or DAPR (.7-.4) = 0, the internal reference voltages correspond to the external
reference voltages V_AGND and V_AREF, respectively.
If V_AINPUT > V , _IntAREF the conversion result is 0FFH, if V_AINPUT < V_IntAGDN , the conversion result is 00H
V( _AINPUT is the analog input voltage).
If the external reference voltages V_AGND = 0 V and V_AREF = +5 V (with respect to V_SS and V_CC) are
applied, then the following internal reference voltages V_IntAGND and V_IntAREF shown in table 7-7 can
be adjusted via the special function register DAPR.
Figure 7-29
Special Function Register DAPR (Address DAH)
0DAH
Programming of V_IntAREF
Programming of V_IntAGND
DAPR
D/A converter program register. Each 4-bit nibble is used to program the internal reference
voltages. Write-access to DAPR starts conversion.
DAPR (.3-.0)
V V = + _IntAGND
AGND
16
(V_AREF – V_AGND)
with DAPR (.3-.0) < 13;
DAPR (.7-.4)
V V = + _IntAGND
AGND
16
(V_AREF – V_AGND)
with DAPR (.7-.4) > 3;
Semiconductor Group
77