- Omega Data Acquisition Adapter Users Manual

4. Register Description and Programming
The DAQ-16 uses 16 consecutive I/O address locations in the range 0 to FFFFH. The card
utilizes these addresses for the registers listed in Table 4-1. (* indicates registers located in
8254 counter).
Read/Write 8-bit 8254 Control Word/Status Register
Base F *
Read/Write 8-bit Multi-function Timer Register
Base E *
Read/Write 8-bit Clock Rate Register (high)
Base + D *
Read/Write 8-bit Clock Rate Register (low)
Base + C *
Reserved
Base 9, A, B
Read/Write 8-bit Digital Input/Output Register
Base + 8
Write only 16-bit D/A Channel 1 Register
Base + 6, 7
Write only 16-bit D/A Channel 0 Register
Base + 4, 5
Write only 16-bit Start Conversion Register
Read only 16-bit A/D Data Register
Base + 2, 3
Read/Write 16-bit Control Word Register
Base + 0, 1
Table 4-1. DAQ-16 Address Map
4.1 Register Description
4.1.1 Control Word Register
The control word register defines and controls many of the DAQ-16's data conversion
functions. This register is 16-bit read/write.
Write Read Write Read
D15 INT2 INT2 D7 RUN RUN
D14 INT1 INT1 D6 0 EOC
D13 INT0 INT0 D5 0 VALID
D12 DMAEN DMAEN D4 0 0
D11 DMACT DMACH D3 0 0
D10 LEVEL LEVEL D2 CHSL2 CHSL2
D9 TRIG TRIG D1 CHSL1 CHSL1
D8 CLK CLK D0 CHSL0 CHSL0
INT2, INT1 and INT0 control the DAQ-16 interrupt source.
INT2 INT1 INT0 DESCRIPTION
0 0 0 Interrupt disabled
1 0 0 Interrupt timer 2
1 0 1 Interrupt on terminal count
1 1 0 External interrupt
1 1 1 Interrupt on end of conversion
DAQ-16 Users Manual 25