Intel386™ EX MICROPROCESSOR USER'S MANUAL
CHAPTER 11
11.1
OVERVIEW ................................................................................................................. 11-1
11.1.1
SIO Signals .............................................................................................................11-3
11.2
SIO OPERATION ........................................................................................................ 11-4
11.2.1
Baud-rate Generator ...............................................................................................11-4
SIO n Transmitter .....................................................................................................11-6
11.2.2
SIO n Receiver .........................................................................................................11-9
11.2.3
11.2.4
Modem Control .....................................................................................................11-12
11.2.5
Diagnostic Mode ...................................................................................................11-12
11.2.6
11.2.6.1
SIO Interrupt Sources ......................................................................................11-13
11.2.6.2
SIO DMA sources ............................................................................................11-13
11.2.7
External UART Support ........................................................................................11-14
11.3
REGISTER DEFINITIONS......................................................................................... 11-15
11.3.1
11.3.2
11.3.3
11.3.4
11.3.5
11.3.6
11.3.7
11.3.8
11.3.9
11.4
11.4.1
CHAPTER 12
12.1
OVERVIEW ................................................................................................................. 12-1
12.1.1
DMA Terminology ...................................................................................................12-3
12.1.2
DMA Signals ...........................................................................................................12-4
12.2
DMA OPERATION....................................................................................................... 12-5
12.2.1
DMA Transfers ........................................................................................................12-5
12.2.2
12.2.2.1
Fly-By Mode .......................................................................................................12-5
12.2.2.2
Two-Cycle Mode ................................................................................................12-6
12.2.2.3
12.2.2.4
12.2.2.5
12.2.3
Starting DMA Transfers ..........................................................................................12-9
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