User guide

26 • Registers
I/O Address Read Write
Base + 0 Counter 0 Counter 0
Base + 4 Counter 1 Counter 1
Base + 8 Counter 2 Counter 2
Base + C ------------- 8254 Counter Control
Base + 10 A/D Data Reg. CH1 D/A Data Reg.
Base + 14 ------------- CH2 D/A Data Reg.
Base + 18 A/D Status Reg. A/D Control Reg.
Base + 1C Digital IN Reg. Digital OUT Reg.
Base + 20 ------------- Software Trigger
Table 3.1 I/O Address
3.2 A/D Data Registers
The PCI-9112 provides 16 single-ended or 8 differential A/D input channels;
the 12bit digital data are stored into the 32bit A/D data registers.
Address: BASE + 10
Attribute: read only
Data Format:
Bit 7 6 5 4 3 2 1 0
BASE+10 AD3 AD2 AD1 AD0 CH3 CH2 CH1 CH0
BASE+11 AD11 AD10 AD9 AD8 AD7 AD6 AD5 AD4
BASE+12 --- --- --- --- --- --- --- ---
BASE+13 --- --- --- --- --- --- --- ---
AD11.. AD0: Analog to digital data. AD11 is the Most Significant Bit (MSB).
AD0 is the Least Significant Bit (LSB).
CH3 ~ CH0: A/D channel number from which the data is derived.
---: Don’t care