Registers Format
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37
4.9 D/A Output Register
The D/A converter will convert the D/A output register data to the analog
signal. The register data of the address Base + 4 and Base + 5 are used
for D/A channel 1, Base +6 and Base +7 are used for D/A channel 2.
Address : BASE + 4 & BASE + 5
Attribute: write only
Data Format: (for D/A Channel 1)
Bit
7
6
5
4
3
2
1
0
Base + 4
DA7
DA6
DA5
DA4
DA3
DA2
DA1
DA0
Base + 5
X
X
X
X
DA11 DA10 DA9
DA8
Address : BASE + 6 & BASE + 7
Attribute: write only
Data Format: (for D/A Channel 2)
Bit
7
6
5
4
3
2
1
0
Base + 6
DA7
DA6
DA5
DA4
DA3
DA2
DA1
DA0
Base + 7
X
X
X
X
DA11 DA10 DA9
DA8
DA0 is the LSB and DA11 is the MSB of the 12 bits data.
X: don't care
Note:
The D/A registers are "
double buffered
" so that the D/A analog
output signals will not updated until the second (
high
) byte is
written. This can insure a single step transition when the D/A
conversion.
4.10 Internal Timer/Counter Register
Two counter of 8254 are used for periodically triggering th e A/D
conversion, the left one is left free for user applications. The 8254
occupies 4 I/O address locations in the ACL-8112 as shown blow. Users
can refer to NEC's or Intel's data sheet for a full description of the 8254
features, condensed information is specified in Appendix B.
Address : BASE + 0 ~ BASE + 3
Attribute:
read / write
Data Format:
Base + 0
Counter 0 Register ( R/W)
Base + 1
Counter 1 Register ( R/W)
Summary of Contents for ACL-8112 Series
Page 1: ...NuDAQ ACL 8112 Series Enhanced Multi Functions Data Acquisition Cards User s Guide ...
Page 4: ......
Page 40: ...32 Registers Format 1 1 1 1 1 000 Unipolar N A Table 4 2 1 Function of the Gain Control Bits ...
Page 44: ...36 Registers Format Base 14 DO15 DO14 DO13 DO12 DO11 DO10 DO9 DO8 ...
Page 46: ...38 Registers Format Base 2 Counter 2 Register R W Base 3 8254 CONTROL BYTE ...
Page 71: ...C Language Library 63 ...
Page 81: ...C Language Library 73 Example See Demo Program AD_Demo4 C ...
Page 85: ...C Language Library 77 ERR_AD_INTNotSet Example See demo program AD_Demo2 C ...
