General Information; Introduction; General Description - HP 3000 Series Installation And Service Manual

GENERAL INFORMATION
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1-1. INTRODUCTION
This section describes the functional and physical characteris-
tics of the HP 30020A Intelligent Network Processor (INP) shown
in figure 1-1. Related publications that may be required for
operation and service of the INP are listed in the Preface.
1-2. GENERAL DESCRIPTION
The HP 30020A Intelligent Network Processor ( frequently referred
to hereafter as the INP) provides the HP 3000 Series 30 and
Series 33 Computer Systems with data communication capabilities
in high-speed as well as low-speed modern environments.
A microprocessor within the INP performs the communications pro-
tocol management, thus relieving the HP 3000 processor of that
task. As power is applied, the INP initializes itself, runs a
mini-diagnostic routine, reports to the system that it is func-
tionally operational, and requests configuration parameters.
When a request for data communication p"erformance is made (for
example, when a user at a terminal opens a DS line), the system
loads the appropriate driver onto the INP. The INP then trans-
fers control to the driver from its background loader program.
The driver opens the communications channel and passes buffered
data back and forth between the HP 3000 CPU and the data
communication channel.
Serialization, protocol management, frame/block management, modem
management, and data buffering are all performed by the INP. The
CPU must still process message formats and higher level link pro-
cedures. While the INP is transferring the last correctly re-
ceived block of data to the CPU, the INP is also processing and
buffering the next block of data corning from the communication
channel.
1-1