Datasheet
3
IEEE 1284-Compatible Parallel Interface Controller — CD1284
Contents
1.0
2.0
Overview
......................................................................................................................12
Conventions
...............................................................................................................15
2.1
Abbreviations.......................................................................................................15
2.2
Acronyms ............................................................................................................15
Pin Information
..........................................................................................................17
3.1
Pin Diagram.........................................................................................................17
3.2
Pin List.................................................................................................................18
Register Summary
...................................................................................................24
4.1
Register Summary Tables...................................................................................24
4.2
Register Usage....................................................................................................27
Functional Description
...........................................................................................31
5.1
Device Architecture.............................................................................................31
5.2
CPU Interface......................................................................................................33
5.2.1
Read Cycles...........................................................................................33
5.2.2
Write Cycles...........................................................................................34
5.2.3
Service-Acknowledge Cycles.................................................................34
5.2.4
DMA Cycles............................................................................................34
5.3
Serial Port Service Requests ..............................................................................35
5.3.1
Interrupts................................................................................................36
5.3.2
DMAREQ* as Parallel Interrupt Source..................................................36
5.3.3
Serial Service Request Polling...............................................................40
5.3.4
Daisy-Chaining Service Requests with CD1400s ..................................41
5.4
Parallel Port Service Requests............................................................................43
5.4.1
Hardware-Activated Context Switch, Parallel.........................................48
5.4.2
Software-Activated Context Switch, Parallel ..........................................49
5.5
Serial Data Reception and Transmission............................................................49
5.5.1
Receiver Operation ................................................................................50
5.5.2
Receiver Timer Operations ....................................................................51
5.5.3
Receive Exceptions................................................................................52
5.5.4
Transmitter Operation ............................................................................54
5.6
Flow Control........................................................................................................55
5.6.1
In-Band Flow Control..............................................................................55
5.6.2
Receiver In-Band Flow Control ..............................................................55
5.6.3
Out-of-Band Flow Control.......................................................................58
5.6.4
Modem Signals and General-Purpose I/O .............................................59
5.7
Receive Special Character Processing...............................................................61
5.7.1
UNIX
Character Processing ..................................................................61
5.7.2
Non-UNIX
Receive Special Character Processing................................63
5.8
Transmit Special Character Processing..............................................................67
5.8.1
Line Terminating Characters..................................................................67
5.8.2
Embedded Transmit Commands............................................................67
5.8.3
Send Special Character Command........................................................68
5.9
Baud Rate Generation.........................................................................................72
3.0
4.0
5.0