Display Circuit; Usb Interface (Host); Dvi Output; Recording/Playback - Kenwood TS-990S Service Manual

TS-990S

10-7. USB Interface (host)

This transceiver incorporates a 2-channel USB host
function and supports USB 2.0 at full speed. The main ap-
plication MCU (IC1) and USB transceiver (IC502) confi gures
a single channel and the main application MCU and USB
transceiver (IC503) confi gures another single channel.
The USB bus power supply uses the HIGH SIDE switch
(IC501) for over-current detection. The interface of the main
application MCU and USB transceiver (IC502 and IC503)
performs 6-pin serial communications.

10-8. DVI output

This transceiver incorporates a DVI-I terminal with analog
and digital video output functions.
The DVI transmitter (IC401) converts RGB888 digital sig-
nals from the main application MCU (IC1) so that digital im-
age signals will be output from the DVI-I terminal (J401) via
the digital visual interface (DVI).
The video DAC (IC402) performs the D/A conversion of
RGB888 digital signals from the main application MCU so
that analog image signals will be output from the DVI-I termi-
nal (J401).
The output images are the same as images output from
the main display.

10-9. Recording/Playback

This transceiver has a recording/playback function. The
ADC (IC7) performs the A/D conversion of analog signals at
a sampling frequency (fs) of 16kHz after the analog signals
are input from the DSP (IC300) of the DSP unit (X53-453).
The converted signals are stored in the main application
MCU (IC1). At the time of playback, the DAC (IC6) performs
the D/A conversion of the digital audio signal memorized in
the main application MCU at an fs of 16kHz and transmits
the converted analog signal to the DSP of the DSP unit.
10-10. Sub Display Interface
The incorporated sub display is a 3.5-inch (320 x 240
resolution) LCD. The sub application MCU (IC201) and the
sub display interface are in mutual RGB888 communication.
RGB888 digital signal output from the sub application MCU
is transferred to the sub display.
10-11. Main Display Interface
The incorporated main display is a 7-inch (800 x 480
resolution) LCD. The interface of the main application MCU
(IC1) and main display performs RGB666 communication.
RGB666 digital signal output from the main application MCU
is applide to the buffer ICs (IC651, IC652, and IC653) where
waveform shaping is performed, and the signal is transferred
to the main display.
10-12. Operating as USB 2.0 (device)
If this transceiver is connected to a PC over a USB cable,
the following three items operate as high-speed USB 2.0 de-
vices.
• USB to UART Bridge (IC702)
Used for PC command communication for the ARCP.
• USB Audio (IC703)
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CIRCUIT DESCRIPTION
USB-B connector (J701) on the rear panel to the PC through
the USB 3-channel hub (IC701).

11. Display Circuit

IC6), a peripheral circuit, LCD assy, LCD backlight block,
and LED block. The display block uses the PTXD, PRXD,
PCTS, and PRTS to communicate with the main MCU (X53-
452 IC46) and uses the PATXD to communicate with the
application MCU (X46-339 IC1) (at a baud rate of 115,200
bps).
11-1. Circuits Around the Panel MCU
are used for the digital block. The panel MCU clock at
11.0592MHz (X101) is used. The reset signal is controlled
from the main MCU. The panel MCU accepts signal the
key matrix, various encoders, various volumes, external PF
key, and the touch panel. The volumes and external PF key
are all accepted from the multiplexer (IC9, IC10, and IC11)
through the A/D port of the panel MCU.
11-2. Touch panel
membrane system. The power supply switches (Q303 to
Q308) for the touch detection X/Y axis are turned ON and
OFF through the panel MCU to control the touch panel.
panel MCU based on the division ratio of the voltage applied
in the x-axis and y-axis direction.
11-3. LCD Backlight Controller
side and IC307 on the sub side. The built-in driver boosts
and the PWM controls the power supply to the backlight to
adjust the brightness of the backlight. The panel MCU is in
PWM control. The LCD backlight controller is under the ON/
OFF control of three MCUs, the main MCU, the application
MCU, and the panel MCU.
11-4. LED
dimmer control. The user can set four levels of brightness.
The panel MCU is in control of 50 LEDs, and each LED not
used for the numeric keypad is driven by a different port. The
panel MCU and shift register (IC7) are in control of the drive
transistor.
The USB audio operates at the time of signal transmis-
sion and reception through the microphone and speaker
connected to the PC or recording the sound received.
• Access to NAND Flash (IC8)
In the case of updating firmware through the PC, the
fi rmware is stored temporarily in the NAND fl ash via the
main application MCU (IC1).
The above three devices are connected through the
The display block consists of the panel MCU (X54-385
Two power supplies, the 5D (5 V) and 33AVR (3.3 V),
The touch panel used for this transceiver is of resistive
The coordinates are accepted through the A/D port of the
The LCD backlight controller uses IC306 on the main
The main display and sub display are under a four-stage