CD1865 —
Intelligent Eight-Channel Communications Controller
4
Datasheet
6.3.2
Interface Examples .............................................................................................54
6.4.1
Interfacing to 80X86-Family Processors ................................................55
6.4.2
Interfacing to 680X0-Family Processors ................................................55
6.4.3
Interfacing to the VME Bus ....................................................................55
Serial Interfaces
........................................................................................................58
7.1
Receiver Operation.............................................................................................58
7.1.1
Basic Operation......................................................................................58
7.1.2
Receive FIFO Operation ........................................................................58
7.1.3
FIFO Timer Operations ..........................................................................60
7.1.4
Receive Service Requests.....................................................................60
7.1.5
Receive Good Data
‰
Service Request.................................................61
7.1.6
Receive Exception Service Request......................................................61
7.1.7
Types of Errors.......................................................................................62
7.1.8
Types of Exceptions...............................................................................62
7.1.9
Flow-Control Characters ........................................................................63
7.1.10 Programming Notes ...............................................................................68
7.2
Transmitter Operation .........................................................................................68
7.2.1
Basic Operation......................................................................................68
7.2.2
FIFO Operation ......................................................................................69
7.2.3
Transmit Service Requests....................................................................69
7.2.4
Special Transmitter Commands.............................................................70
7.2.5
Special Character Transmission by Send
Special Character Command.................................................................70
7.2.6
Embedded Transmit Commands............................................................70
7.2.7
Sending Breaks......................................................................................71
7.2.8
Sending Inter-Character Delays.............................................................71
7.2.9
Summary of Special Transmitter Commands.........................................71
7.3
Flow Control........................................................................................................72
7.3.1
Receiver Flow Control............................................................................72
7.3.2
Receiver Hardware (Out-of-Band) Flow Control ....................................73
7.3.3
Receiver Software (In-Band) Flow Control.............................................74
7.3.4
Transmitter Flow Control........................................................................75
7.3.5
Transmitter Hardware (Out-of-Band) Flow Control ................................76
7.3.6
Transmitter Software (In-Band) Flow Control.........................................76
7.4
Modem Signals and General-Purpose I/O ..........................................................78
7.4.1
Generating Service Requests with Modem Pins....................................80
7.4.2
Using Modem Pins as General-Purpose I/O..........................................80
7.5
Testing the CD1865
—
Loopback Tests.............................................................80
Programming
.............................................................................................................83
8.1
Types of Registers..............................................................................................83
8.2
Access Duty Cycle ..............................................................................................84
8.3
Accessing FIFOs Versus Other Registers ..........................................................84
8.4
Initialization .........................................................................................................84
8.5
Global Register Initialization................................................................................86
8.6
Service Request Initialization..............................................................................86
8.7
Prescaler.............................................................................................................86
8.8
Channel Initialization and Changes.....................................................................87
Unclocked Versus Clocked Bus Interface..............................................52
6.4
7.0
8.0