BLOCK DIAGRAM DESCRIPTION (RX)
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1. The Media Processor(EM8620L)
The media processor which is used in this product is the EM8620L of Sigma Designs. The EM8620L consists of CPU and
decoder. The CPU is a ARM7TDMI core and the decoder covers MPEG-2, MPEG-4, WMV9 and Divx. Also the EM8620L
has many built-in functions that they are PCI/Peripheral BUS, Digital Audio Processor, Video/Graphic processor and Double-
Data Rate SDRAM Controller etc.
In this product the PCI Bus controls a wireless LAN card of MiniPCI type and Digital Audio Processor controls a DAC device
externally that it converts digital audio data into analogue audio signal. Also the Graphics controller sends 24 bit digital RGB
data to a LVDS device. The LVDS device interfaces with LCD module.
2. Wireless LAN
The Wireless LAN Card which is used in the product is manufactured by LG Innotek. The card satisfied with IEEE802.11 b/g
standard. The product name is LVMM-3001A.
The maximum bandwidth of LVMM-3001A is 54Mbps and its operation frequency is about 2.4GHz.
3. DDR SDRAM
The receiver has total 64Mbytes double-data rate SDRAM. 16Mbytes of 64Mbytes is the space for the decoder and the rest
is for applications. The speed of the SDRAM is 166MHz. We use ferrite beads and capacitors on the clock lines to reduce
EMI. SDRAM devices use 2.5V and 1.2V for operational voltages.
4. Clock of the Media Processor(EM8620L)
Internal PLL circuit of the EM8620L generates three clock signals using 27MHz crystal oscillator input. One is 166MHz clock
of the SDRAM input, another is 65MHz clock of the Digital RGB part, and the third is 24.576MHz of Audio part.
5. UART(RS-232)
EM8620L has two on-chip UARTs. The UART0 is used for system debugging, and the UART1 is used to communicate with
the microcontroller. The Information of key button control, battery, and power management that the microcontroller gets, is
transported to the UART1 interface of EM8620L
6. Audio Interface
EM8620L has a built-in digital audio processor that it is able to decode MP3 files or WMA files. The decoded data is
transported into WM8728, DAC Chip and it converts digital input data to analog signals. These signals are transmitted to
speaker via TPA6011A4, Audio Amplifier.
7. Flash Memory
RM-15LW10 has two kinds of program memory. One is serial flash memory; the other is parallel flash memory. In serial flash
memory, it is stored the program that initializes the CPU and peripherals before loading OS to main memory, and this
program is called 'bootloader'. The OS to control the system is stored in the parallel flash memory. Bootloader stored in
serial flash reads the OS image from the parallel flash and writes the image to the DRAM and then, launches the OS loaded
into DRAM.
8. Digital RGB
EM8620L displays the video in LCD panel by transmitting the digital RGB signal to external LVDS chip. The digital RGB
signals that consist of 24-bit color, horizontal sync, vertical sync, and 65MHz clock are transmitted to LVDS chip. The signals
are converted to Low Voltage Differential Signal and sent to the LCD panel.
9. Microcontroller
An 8051-compatible 8-bit microcontroller, CS8954 controls battery management, key button, remote control, and power
management in this system. It controls battery-charging and discharging status, and manages audio volume, channel, and
remote control signal. It also plays a role of system power manager to control power supply effectively.
