F800 CIRCUIT DESCRIPTION
19 (25)
Uppgjord (även faktaansvarig om annan) -
Prepared (also subject responsible if other)
Nr
-
No.
KL/ECS/S/LT Magnus Lindahl
ECS/S/LT-96:5044
Dokansv/Godk -
Doc respons/Approved
Kontr
-
Checked
Datum
-
Date
Rev
File
KI/ECS/S/LTC
1996-06-06
A
965044.DOC
PROCESSOR BOARD
The same kind of CPU boards are used in all versions of F800. The CPU board
contains a number of hardware functions. The majority of the hardware functions are
controlled by the software. A few logic functions and features of the F800 are
implemented as pure hardware functions. In general a function consists of a
combination of hardware and software. The function blocks described here will be
described as a mixture of hardware and software.
The CPU board can be used together with an option board.
The CPU board is divided into the following major function blocks :
#"
An 8- bit processor with peripheral circuits.
#"
AF circuits for speech
#"
AF circuits for tone signalling
#"
I/O circuits for communication with external units
#"
I/O circuits for internal communication
#"
Interface for the radio board
#"
Interface for option board
#"
DC power supply and distribution
The CPU board is fitted with two external, D- type, and five internal, strip, connectors.
The majority of the components are surface mounted to the multi-layer PCB. The
processor and the memory circuits are all mounted in IC holders. The CPU board is
mounted in the F800 chassis with 8 screws to obtain proper grounding. To further
improve the grounding and to avoid interference etc. the CPU board is fitted with
ground strips on the edges of the board. The CPU board is replaced as one unit
during normal field service. The CPU board requires no tuning.
Processor and peripheral circuits
The CPU board is equipped with a V20 microprocessor, equal to 80C88, and
peripheral circuits from the same family. The microprocessor, Z1, uses an external
crystal controlled oscillator as clock, Y1, Z16A. The clock frequency is 4,6080 MHz.
The clock is also made available for the option board via P406:3.
