Measurement Computing PPIO-AI08 User Manual
Page 12
5.3
PPIO-AI08 REGISTERS
The PPIO-AI08 register descriptions follow the format:
CH1
CH2
CH4
CH8
A/D12
LSB
A/D11
A/D10
A/D9
0
1
2
3
4
5
6
7
Where the numbers along the top row are the bit positions within the 8-bit byte and
the numbers and symbols in the bottom row are the functions associated with that bit.
To write to or read from a register in decimal or
HEX,
the following weights apply:
80
128
7
40
64
6
20
32
5
10
16
4
8
8
3
4
4
2
2
2
1
1
1
0
HEX VALUE
DECIMAL VALUE
BIT POSITION
To write control or data to a register, the individual bits must be set to “0” or “1”, then
combined to form a byte.
The registers and their function are listed on the following table. Each register has
eight bits which can constitute a byte of data or eight individual set/read functions.
OP1 - OP4,
INTE
&
MUX
Address
EOC,
IP1-IP3,
IRQ,
MUX
Address
BASE
+ 2
Start 8 bit A/D conversion
A/D Bits 9-12(LSB)
BASE
+ 1
Start 12 bit A/D conversion
A/D Bits 1(MSB)
−8
BASE
+ 0
WRITE FUNCTION
READ FUNCTION
ADDRESS
8