BIT STRING NAME
DIRECTION
CONNECTOR PIN POSITION
PHYSICAL I/O TYPE
DB[15:0]
--->
J7.16 (DAC_OUT_2)
Analog Output
Description
Each channel is updated once the MSB is written. Writing only the MSB will update the DAC channel output. The results of
changing jumper settings at J5 will only take affect after writing the MSB on the DAC output. The two 8-bit DAC registers can be
written simultaneously by writing the data as a 16-bit I/O transaction (Examples: “out dx, ax” or “outpw(base_4,
dac_value)” ).
DAC outputs are available in either DAS16jr/16 or DAS1602 modes. The DAC outputs are always enabled and available for use.
The DAC output bit alignments can be adjusted for either 12-bit legacy operation or full 16-bit DAC mode.
POWER UP or RESET
At power-up or reset the DAC outputs are at set to zero volts.
OUTPUT VOLTAGE CONVERSION
OUTPUT
RANGE
DB1_UB
J5 *
DB1_R
J5 *
RESOLUTION
NEG FULL
SCALE
VOLTAGE
POS FULL
SCALE
VOLTAGE
NEG FULL
SCALE
HEX
POS FULL
SCALE
HEX
+/- 10 Volts
1
1
305 uV
-10.00
+10.00
0x0000
0xFFFF
+/- 5 Volts
1
0
153 uV
-5.000
+5.000
0x0000
0xFFFF
0 - 10 Volts
0
1
153 uV
0.000
+10.00
0x0000
0xFFFF
0 - 5 Volts
0
0
76 uV
0.000
+5.000
0x0000
0xFFFF
* '1' = Jumper installed. '0' = Jumper not installed.
See Also
Register Summary ( see page 41)
Example
Examples of how to write to the DAC output register in 16-bit DAC mode.
8-Bit Writes in C/C++:
unsigned int dac_value;
...
outp( base_6, dac_value & 0xFF );
outp( base_7, dac_value >> 8 );
...
STX104 Reference Manual
11.14 DAC Channel-B (Offset=6)
Copyright © 2009 by
Apex Embedded Systems
. All rights reserved.
58
Thursday, October 08, 2009
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