Digital Control Circuit; Application Mcu And Its Periphery; Communication With The Main/Panel Mcu; Lan Interface Circuit - Kenwood TS-990S Service Manual

10. Digital Control Circuit

10-1. Outline
The digital unit (X46-339) mainly consists of two applica-
tion MCUs (IC1 and IC201). IC1 mainly controls the main
25MHz
X601
RJ-45
Ether PHY IC
J601 IC601
USB transceiver
IC502/IC503
Front
Panel
High side SW
USB-A
IC501
DVI transmitter
IC401
DVI-I
J401
Video DAC
IC402
24MHz
X701
Rear
USB 3ch HUB
USB-B
IC701
J701
USB to UART
Main
bridge
MCU
IC702
12MHz
X702
USB audio
IC703
SRX
DSP
DAC IC
ADC IC

10-2. Application MCU and Its Periphery

The main application MCU (ICI) and sub application
MCU (IC201) are the same in basic confi guration. The clock
frequency is 26MHz and the internal operating frequency
is 600MHz. As for the memory confi guration, 2G-bit NAND
flash memories (IC8 and IC208) for program storage and
1G-bit DDR2 memories (IC2/IC3 and IC202/IC203) for pro-
gram computation are incorporated.
Two application MCUs are in UART communication at a
baud rate of 3,686,400 bps. Three types of supply voltages
in fi ve systems are used, i.e., 1.8 V (for the DDR controller
system), 3.3 V (for the I/O system), 1.2 V (for the core), 1.8
V (for others), and 3.3 V (for the USB system), and started in
the sequence shown in Fig. 44.
1.8V
DDR controller system
I/O system 3.3V
Core
1.8V (for others)
USB system
Fig. 44 Power supply voltage of the application MCU
CIRCUIT DESCRIPTION
RMII
6pin Serial
Main application MCU
Sub application MCU
12.288MHz
X202
IC6
Clock circuit
IC209
IC7
Fig. 43 Digital control circuit
1.2V
1.8V
3.3V
display and external monitor output system (7-inch LCD,
IC401, and IC402), USB host transceiver (IC502 and IC503),
and Ethernet PHY IC (IC601) while IC201 is mainly in con-
trol of the sub display (3.5-inch LCD).
26MHz
X1
UART
IC1 UART
SPI
UART
26MHz
X201
IC201
10-3. Communication with the Main MCU
The application MCU is basically operated by commands
from the main MCU (IC46) of the control unit (X53-452).
These commands are transmitted in UART communication
at a baud rate of 115,200 bps.
10-4. Communication with the Scope DSP
Scope image data displayed on the main display and sub
display is received by both IC1 and IC201 from the scope
DSP (IC380) of the control unit in serial peripheral interface
(SPI) mode. The transfer baud rate is 2,073,600 bps.
10-5. Communication with the Panel MCU
Coordinate data on the scope screen of the main display
is received through the panel MCU (IC6) of the display unit
(X54-385). The transfer baud rate is 115,200 bps.

10-6. LAN Interface Circuit

The LAN interface of this transceiver supports 100BASE-
TX and 10BASE-T standards, and consists of the MAC func-
tion of the main application MCU (IC1), PHY function of the
Ethernet PHY IC (IC601), and the transformer-built-in RJ-45
connector (IC601). The MAC interface communicates over
RMII.
TS-990S
NAND flash
IC8
DDR2
IC2/IC3
Panel MCU
Main MCU
Scope DSP
Buffer IC To Main display
(7inch 800×480)
IC651/IC652/IC653
NAND flash
IC208
DDR2
IC202/IC203
To Sub display
(3.5inch 320×240)
37