Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
391
/
631
Figure 18-3 Tine diagram of transitions with trigger disable
DAC output voltage
The digital input is converted to analog voltage output by a DAC module in a linear relationship ranging from 0 to
VREF+.The output voltage of DAC is calculated as follows:
DAC output = V
REF
X (DATO / 4095).
DMA requests
DAC_CTRL1.DMAEN = 1 is configured to enable DMA function. When an external trigger occurs (not a software
trigger), a DMA request is generated and the data aligned with the data hold register is then transferred to the
DAC_DATO register.
Note: DMA requests for DAC have no accumulative function, and when the second external trigger occurs before the
response to the first external trigger, the second DMA request cannot be processed and there is no error reporting
mechanism.
The noise
DAC can generate noise, by configuring DAC_CTRL.WEN[1:0] to "01" to turn on the noise function, by configuring
DAC_CTRL.MASEL[3:0] to select which bits of the linear feedback shift register (LFSR) are masked, the value of
LFSR is added to the value of the DAC alignment data holding register and written to the DAC_DATO register
(overflow bits are discarded). The initial value of LFSR is 0xAAA, and the value of LFSR is updated after 3 APB1
cycles after the trigger event occurs.
APB1_CLK
DACCHxD
DATOx
0x10B
0x10B
t
SETTLING
DACx_OUT