User manual

ATHENA CPU User Manual V1.40 Page 3
12.1 Select the input channel ............................................................................................................52
12.2 Select the input range................................................................................................................ 52
12.3 Wait for analog input circuit to settle .......................................................................................52
12.4 Perform an A/D conversion on the current channel ................................................................. 53
12.5 Wait for the conversion to finish ...............................................................................................53
12.6 Read the data from the board....................................................................................................53
12.7 Convert the numerical data to a meaningful value ...................................................................54
13. A/D S CAN , I NTERRUPT , AND FIFO O PERATION ..............................................................................55
13.1 Athena A/D Operating Modes ................................................................................................... 56
14. A NALOG O UTPUT R ANGES AND R ESOLUTION ................................................................................. 57
14.1 Description................................................................................................................................ 57
14.2 Resolution..................................................................................................................................57
14.3 Output Range Selection............................................................................................................. 57
14.4 D/A Conversion Formulas and Tables......................................................................................58
15. G ENERATING AN A NALOG O UTPUT ............................................................................................... 60
15.1 Compute the D/A code for the desired output voltage ..............................................................60
15.2 Write the value to the selected output channel..........................................................................60
15.3 Wait for the D/A to update ........................................................................................................ 60
16. A NALOG C IRCUIT C ALIBRATION ....................................................................................................61
16.1 A/D bipolar offset......................................................................................................................61
16.2 A/D unipolar offset....................................................................................................................61
16.3 A/D full-scale ............................................................................................................................ 61
16.4 D/A full scale............................................................................................................................. 61
17. D IGITAL I/O O PERATION ................................................................................................................ 62
18. C OUNTER /T IMER O PERATION ....................................................................................................... 63
18.1 Counter 0 – A/D Sample Control ..............................................................................................63
18.2 Counter 1 – Counting/Totalizing Functions..............................................................................63
18.3 Command Sequences................................................................................................................. 64
19. W ATCHDOG T IMER P ROGRAMMING ..............................................................................................66
19.1 Watchdog Timer ........................................................................................................................ 66
19.2 Watchdog Timer Register Details ............................................................................................. 67
19.3 Example : Watchdog Timer With Software Trigger ..................................................................69
19.4 Example : Watchdog Timer With Hardware Trigger................................................................69
20. D ATA A CQUISITION S PECIFICATIONS ............................................................................................70
21. F LASH D ISK M ODULE ..................................................................................................................... 71
21.1 Installing the Flashdisk Module................................................................................................71
21.2 Configuration .......................................................................................................................71
21.3 Using the Flashdisk with Another IDE Drive ................................................................... 71
21.4 Power Supply ......................................................................................................................71
22. F LASH D ISK P ROGRAMMER B OARD ..............................................................................................72
23. I/O C ABLES ...................................................................................................................................73
24. Q UICK S TART G UIDE ...................................................................................................................... 74
24.1 General Setup............................................................................................................................ 74
24.2 IDE Configuration ....................................................................................................................74
24.3 Booting into MS-DOS, FreeDOS or ROM-DOS .......................................................................75
24.4 Booting into Linux or Microsoft Windows ................................................................................75