AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 264

• Manufacturer Part Number: AT90PWM216-16SE
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable flash
• Manufacturer: ATMEL [ATMEL Corporation]

22.4.2.2
264
AT90PWM216/316
DALA = 1
To work with the 10-bit DAC, two registers have to be updated. In order to avoid intermediate
value, the DAC input values which are really converted into analog signal are buffering into
unreachable registers. In normal mode, the update of the shadow register is done when the reg-
ister DACH is written.
In case DAATE bit is set, the DAC input values will be updated on the trigger event selected
through DATS bits.
In order to avoid wrong DAC input values, the update can only be done after having written
respectively DACL and DACH registers. It is possible to work on 8-bit configuration by only writ-
ing the DACH value. In this case, update is done each trigger event.
In case DAATE bit is cleared, the DAC is in an automatic update mode. Writing the DACH regis-
ter automatically update the DAC input values with the DACH and DACL register values.
It means that whatever is the configuration of the DAATE bit, changing the DACL register has no
effect on the DAC output until the DACH register has also been updated. So, to work with 10
bits, DACL must be written first before DACH. To work with 8-bit configuration, writing DACH
allows the update of the DAC.
Bit
Read/Write
Initial Value
DAC9
DAC1
R/W
R/W
7
0
0
DAC8
DAC0
R/W
R/W
6
0
0
DAC7
R/W
R/W
5
0
0
-
DAC6
R/W
R/W
4
0
0
-
DAC5
R/W
R/W
3
0
0
-
DAC4
R/W
R/W
2
0
0
-
DAC3
R/W
R/W
1
0
0
-
DAC2
R/W
R/W
0
0
0
-
7710D–AVR–08/09
DACH
DACL