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1 control word register, 1 register description, Register description and programming – Omega Engineering DAQ-12 User Manual

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4. Register Description and Programming

The DAQ-12 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 A, B

Read/Write 8-bit Gain Control Register

Base 9

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-12 Address Map

4.1

Register Description

4.1.1

Control Word Register

The control word register defines and controls many of the DAQ-12'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

DMASL

DMASL

D11

DMACT

DMACH

D3

CHSL3

CHSL3

D10

LEVEL

LEVEL

D2

CHSL2

CHSL2

D9

TRIG

TRIG

D1

CHSL1

CHSL1

D8 CLK

CLK

D0

CHSL0

CHSL0

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