The Function Cards; Typesofcard; Master Cards; Mpb Interface - HP M2350A Service Manual

Understanding the Computer Module
The Function Cards
The Function Cards
This section describes the different types of function cards used and their similarities. Each
card is then explained in detail.
Types of Card
There are two basic types of function card:
n
Master Cards
n
Local Cards
The master cards are those cards that have both a central processing unit (CPU) and a Message
Passing Bus interface (MPB-IF). These cards may also communicate with LOCAL cards over the
LOCAL Bus.
The local cards have no MPB-IF chip and can only communicate with the master card via the
LOCAL Bus within a cluster of connectors. These cards are used in clusters containing a master
card.
Master Cards
The following master cards are used in the computer module:
CPC
0
DSPC
CDSPCXTRL
UTIL-CPU
RS232-IF
HDLC-IF
Configurable Processor Card - This card is responsible for all the data
processing of the HP Component Central Monitor. The CPC receives data from
the MPB, processes that data, and places the results back on the MPB.
Monochrome display controller - This controls the monochrome video
display. In addition there may be a language-specific local card (for example
DSPCKANJI for KANJI character set).
Color display controller - This card, together with the CDSPC-VIDEO card,
controls the color video display.
Utility CPU - This derives the system clocks and synchronization as well as
interfacing directly to the HP-HIL devices. The UTIL-CPU may interface
indirectly via the LOCAL Bus to SDN and the Plug-in Module Racks using
LOCAL cards SDN-IF and RACK-IF respectively.
RS232 Interface - This allows the computer module to
be
connected to any
equipment with an RS232 or RS422 interface (for example: a local printer).
There is no connection to the Local Bus on this card.
HDLC Interface - This card provides the computer module with an interface to
real-time wave recorders which use the Standard Recorder Interface Protocol
(STRIP). There is no connection to the Local Bus on this card.
MPB
Interface
All master cards are fitted with the MPB Interface so they can pass data to and from the
Message Passing Bus (MPB). There is no central management system for the MPB as each
master card can perform Bus Arbitration. This means that the cards themselves are responsible
when data is "broadcast" on the MPB.
The MPB Interface consists of a custom IC and an external SRAM used as a pair of receive and
transmit FIFOs, as shown in the following figure.