adc-44d ETC-unknow, adc-44d Datasheet - Page 35

• Manufacturer Part Number: adc-44d
• Description: Multi-function Analogue Input/output Card
• Manufacturer: ETC-unknow

Chapter 5
DAC Section
The Digital to Analogue Converter is accessed as 4 ports. These ports are
mapped into the PC at the following addresses.
An interrupt may be generated if required whenever a channel is updated. Note
that reading port Base + 1 resets the DAC internal control logic only. It does
not clear the DAC control register bits.
The DAC section operates in one of two modes, I/O or DMA.
To output data to the DAC in I/O mode use the following sequence:
Switch on the DAC reference to enable the outputs by setting bit 2 of Base + 1.
Blue Chip Technology Ltd.
Write 0 to Base + 1 (DAC Control Register).
Write 0 to Base + 6 to enable all the DAC outputs.
Write the channel number required into bits 0 and 1 of Base + 1.
Write the least significant byte of DAC data into Base + 0.
Write the most significant byte of DAC data into Base + 0.
ADDRESS
Base + 0
Base + 1
Base + 2
Base + 6
Write DAC Output Data,
low 8 bits on first write, high 4 bits on second
write
DAC Control register
Read resets DAC internal control logic.
Does not clear the DAC control register bits
Write starts a DAC transfer in DMA mode
Bits 0 to 3 enable or disable writes to DAC
channel 0 to 3 respectively
Operation of the Card
FUNCTION
READ/W
RITE
W
W
W
W
R
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