I/O Register Definitions
Note: In the register descriptions, below, writes to an undefined bit have no effect. Reads of an
undefined bit return the value zero.
Main Register Set Definitions
Start A/D Conversion: Base+0 (Write)
Bit:
7
6
5
4
3
2
1
0
Name:
ADSTART
ADSTART Writing any value to this register starts an A/D conversion, unless a conversion is already in progress
(AD_BUSY high). An A/D conversion starts even if the board is set up for interrupt, DMA or
external trigger mode.
A/D LSB (bits 7-0): Base+0 (Read)
Bit:
7
6
5
4
3
2
1
0
Name:
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
AD7-AD0 A/D data bits 7 - 0; AD0 is the LSB.
Auxiliary Digital Output: Base+1 (Write)
Bit:
7
6
5
4
3
2
1
0
Name:
-
-
-
-
LED
DOUT2
DOUT1
DOUT0
LED
Toggles the on-board user LED; 1 = on, 0 = off.
DOUT2-0 Auxiliary digital output bits on analog I/O header CN12. Two pins also serve as optional counter
outputs based on control register bits at Base+10:
DOUT2 - CN12, pin 28. Counter 2 output when OUT2EN = 1 (Base+10, bit 5).
DOUT1 - CN12, pin 30.
DOUT0 - CN12, pin 27. Counter 0 output when OUT0EN = 1 (Base+10, bit 4).
Diamond Systems Corporation
Poseidon User Manual
Page 56
