User manual

Contents
4
PROGRAMMABLE REGISTERS...............................................................................................78
BAUD RATE DIVISORS ...............................................................................................78
DIVISOR LATCH LSB AND MSB..................................................................................79
INTERRUPT CONTROL REGISTER ............................................................................80
INTERRUPT STATUS REGISTER................................................................................81
LINE CONTROL REGISTER ........................................................................................82
LINE STATUS REGISTER............................................................................................83
MODEM CONTROL REGISTER...................................................................................83
MODEM STATUS REGISTER......................................................................................84
ADDITIONAL INFORMATION ...................................................................................................84
9. CENTRONICS PRINTER INTERFACE..............................................................................................85
PROGRAMMABLE REGISTERS...............................................................................................85
LINE PRINTER DATA REGISTER................................................................................85
LINE PRINTER STATUS REGISTER............................................................................85
LINE PRINTER CONTROL REGISTER ........................................................................86
ADDITIONAL INFORMATION ...................................................................................................86
10. PARALLEL I/O................................................................................................................................87
FUNCTIONAL DESCRIPTION ..................................................................................................87
OUTPUT LATCH ..........................................................................................................88
OUTPUT BUFFER........................................................................................................88
INPUT BUFFER............................................................................................................89
PROGRAMMABLE REGISTERS...............................................................................................89
16C50A STANDARD OPERATING MODE ...................................................................89
16C50A ENHANCED OPERATING MODE ...................................................................90
11. SYSTEM REGISTERS.....................................................................................................................96
PROGRAMMABLE REGISTERS...............................................................................................96
ADDITIONAL INFORMATION ...................................................................................................98
12. WATCHDOG TIMER .......................................................................................................................99
WATCHDOG TIMER OPERATION ...........................................................................................99
PROGRAMMABLE REGISTERS.............................................................................................100
WATCHDOG TIMER CLEAR REGISTER...................................................................101
WATCHDOG TIMER STATUS REGISTER.................................................................101
WATCHDOG TIMER COUNTER REGISTERS ...........................................................102
WATCHDOG TIMER RELOAD REGISTERS..............................................................103
ADDITIONAL INFORMATION .................................................................................................103
13. LOCAL BUS VIDEO......................................................................................................................104
14. NUMERIC DATA PROCESSOR....................................................................................................105
15. PROGRAMMABLE LED................................................................................................................106
16. AC POWER FAIL ..........................................................................................................................108
A. JUMPER CONFIGURATIONS ........................................................................................................109
JUMPER OPTIONS ................................................................................................................109
JUMPER DESCRIPTIONS..........................................................................................111
B. SPECIFICATIONS ..........................................................................................................................116
ELECTRICAL AND ENVIRONMENTAL SPECIFICATIONS.....................................................116
ABSOLUTE MAXIMUM RATINGS ..............................................................................116
DC OPERATING CHARACTERISTICS.......................................................................116
BATTERY BACKUP CHARACTERISTICS..................................................................117
STD BUS LOADING CHARACTERISTICS .................................................................117
MECHANICAL SPECIFICATIONS...........................................................................................120
CARD DIMENSIONS AND WEIGHT...........................................................................120
CONNECTORS ..........................................................................................................121