Athena IIII User Manual Rev A.00
www.diamondsystems.com
Page
45
Base + 0
Read
A/D LSB
Bit No.
7
6
5
4
3
2
1
0
Name
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
Reset
0
0
0
0
0
0
0
0
AD7 - 0
A/D data bits 7 - 0; AD0 is the LSB; A/D data is an unsigned 16-bit value.
The A/D value is derived by reading two bytes from Base + 0 and Base + 1 and applying the following formula:
A/D value = (Base + 0 value) + (Base + 1 value) * 256
The value is interpreted as a twos complement 16-bit number ranging from
–32768 to +32767. This raw A/D value
must then be converted to the corresponding input voltage and/or the engineering units represented by that
voltage by applying additional application-specific formulas. Both conversions (conversion to volts and then
conversion to engineering units) may be combined into a single formula for efficiency.
Base + 1
Write
Enhanced Features
Access Register
Bit No.
7
6
5
4
3
2
1
0
Name
-
-
-
-
-
-
PG1
PG0
Reset
0
0
0
0
0
0
0
0
This register has dual function. When 0xA5 and 0xA6 is written to this register nothing happens and the page bits
PG1-0 are preserved. The 0xA5, 0xA6 functionality is kept to provide backward compatibility with existing code. In
order to change the page, the PG1-0 bits should be changed. These bits are duplication of the page bits in Base +
3 register.
This register is different than in Athena-II and provides faster performance to access registers in other pages.
Page Select (0 - 2): Accessible any time to select any of the 3 pages.
Base + 1
Read
A/D MSB
Bit No.
7
6
5
4
3
2
1
0
Name
AD15
AD14
AD13
AD12
AD11
AD10
AD9
AD8
Reset
0
0
0
0
0
0
0
0
AD15 - 8
A/D data bits 15
– 8; AD15 is the MSB; A/D data is an unsigned 16-bit value.
See Base + 0 Read on the previous page for information on A/D values and formulas.