Omega Vehicle Security DAQ-16 user manual Register Description, Control Word Register

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).

Base + 0, 1	Read/Write 16-bit Control Word Register
Base + 2, 3	Write only	16-bit Start Conversion Register
	Read only	16-bit A/D Data Register
Base + 4, 5	Write only	16-bit D/A Channel 0 Register
Base + 6, 7	Write only	16-bit D/A Channel 1 Register
Base + 8	Read/Write	8-bit	Digital Input/Output Register
Base 9, A, B	Reserved
Base + C *	Read/Write	8-bit	Clock Rate Register (low)
Base + D *	Read/Write	8-bit	Clock Rate Register (high)
Base E *	Read/Write	8-bit	Multi-function Timer Register
Base F *	Read/Write	8-bit	8254 Control Word/Status Register

Table 4-1. DAQ-16 Address Map

4.1Register Description

4.1.1Control 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