Kenwood TS-2000 Service Manual page 23

Firmware
The main microcomputer firmware includes adjustment
firmware and user firmware. When repairs or adjustments
are made in service, the user firmware must be rewritten to
make adjustment firmware. It must be restored to the origi-
nal user firmware after repairs or adjustments. The adjust-
ment firmware provides a warning display and a warning
sound when the power goes on.
DSP Circuit
Outline
The TS-2000/X DSP circuit is composed of two DSPs
(IC515 and IC516) and CODEC ICs (IC518, IC522 and
IC523), an input latch circuit, flash ROM (IC504 and IC508).
It is connected with the main microcomputer (IC8) by an
address bus and a data bus through the voltage conversion
ICs (IC9, ID10 and IC11). The SSB, CW, AM and FSK detec-
tion, modulation and AGC operation are done by the DSP,
and digital processing (digital filtering, noise reduction, etc.)
is performed in all modes.
DSP
The DSP operates with an internal core voltage of 1.8V,
an external I/O voltage of 3.3V and an internal frequency of
99.5328MHz (11.0592MHz x 9).
The two DSPs perform the respective IF processing and
AF processing. The IF processing is done by DSP2 (IC515)
and a 24 bit CODEC IC (IC518) is connected to it. DSP2
performs detection, modulation, AGC processing and IF
digital filtering. It is designed so it does not exceed the pro-
cessing time, even if the main band transmission and recep-
tion and sub-band reception are done simultaneously. An
output latch circuit is connected to DSP2 to convert the ana-
log AGC voltage signal from digital to analog before output.
The conversion is done by the ladder resistance method.
The AF processing is done by DSP1 (IC516) and a 16 bit
CODEC IC (IC522, IC523) is connected to it. DSP1 performs
the speech processing (signaling generation, detection,
noise reduction, speech filtering, and various volume pro-
cessing). The input latch circuit is connected to DSP1 and
various signals from the main microcomputer and the micro-
phone selection signal are input into it.
CIRCUIT DESCRIPTION
ROM (IC508 and IC504) connected to DSP1 and DSP2.
tem. DSP2 carries out 32 bit digital processing for detection
and modulation. The operation of this IC is controlled by the
main microcomputer.
AF signal system. These IC outputs directly enter the AF
amplifier, are amplified and then output from the speaker.
The IC input consists of the MIC input and the optional
speech synthesis unit (VS-3).
are generated and supplied by a 12.288MHz quartz crystal
and a peripheral circuit.
and perform such interchanges as audio signals for trans-
mission processed in DSP1, received speech signals de-
tected in DSP2 and information from the DSP1 input latch
circuit. If this interchange does not go well when the power
starts up, a "DSP COMM" error will be displayed on the
LCD and the fact that the DSPS is not operating will be noti-
fied to the main microcomputer. Likewise, when the con-
tent of the flash ROM is abnormal, a "DSP COMM" error is
displayed.
TS-2000/X
Flash ROM
The respective programs and data are stored in the Flash
CODEC IC
A 24 bit CODEC IC (IC518) is used as the IF signal sys-
Two 16 bit CODEC ICs (IC522 and IC523) are used as the
The various timing signals required by both CODEC ICs
Communication between DSPs
DSP1 and DSP2 are connected via serial communication
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