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4.2.  SYSTEM  BLOCK  DIAGRAM

A sample system block diagram for the MT1379 DVD player board design is shown in the
following figure:

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5. AUDIO OUTPUT

The MT1379 supports two-channel and six-channel analog audio output. In a system configuration with six analog outputs,

the front left and right channels can be configured to provide the stereo (2 channel) outputs and Dolby Surround, or the left and

right front channels for a 5.1 channel surround system.
The MT1379 also provides digital output in S/PDIF format. The  board supports both optical and coaxial SPDIF outputs.

6. AUDIO DACS

The MT1379 supports several variations of an I

2

S type bus, varying the order of the data bits (leading or no leading zero bit,

left or right alignment within frame, and MSB or LSB first) is possible using the MT1379 internal configuration registers. The

I

2

S format uses four stereo data lines and three clock lines. The I

2

S data and clock lines can be connected directly to one or

more audio DAC to generate analog audio output.

The two-channel DAC is an AKM AK4382A. The DACs support up to 192kHz sampling rate.

The outputs of the DACs are differential, not single ended so a buffering circuit is required. The buffer circuits use National

LM833 op-amps to perform the low-pass filtering and the buffering.

7. VIDEO INTERFACE

7.1.  VIDEO  DISPLAY  OUTPUT

The video output section controls the transfer of video frames stored in memory to the internal TV encoder of the MT1379. The

output section consists of a programmable CRT controller capable of operating either in Master or Slave mode.

The video output section features internal line buffers which allow the outgoing luminance and chrominance data to match

the internal clock rates with external pixel clock rates, easily facilitating YUV4: 2:2 to YUV4: 2:0 component and sample

conversion. A polyphase filter achieves arbitrary horizontal decimation and interpolation.

Video Bus
The video bus has 8 YUV data pins that transfer luminance and chrominance (YUV) pixels in CCIR601 pixel format (4:2:2).

In this format, there are half as many chrominance (U or V) pixels per line as luminance (Y) pixels; there are as many

chrominance lines as luminance.

Video Post-Processing
The MT1379 video post-processing circuitry provides support for the color conversion, scaling, and filtering functions through

a combination of special hardware and software. Horizontal up-sampling and filtering is done with a programmable, 7-tap

polyphase filter bank for accurate
non-integer interpolations. Vertical scaling is achieved by repeating and dropping lines in accordance with the applicable

scaling ratio.

Video Timing
The video bus can be clocked either by double pixel clock and clock qualifier or by a single pixel clock. The double clock typically

is used for TV displays, the single for computer displays.

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8.  FLASH  MEMORY

The decoder board supports 70ns Flash memories. Currently 4 configurations are supported:

• FLASH_512K_8b
• FLASH_1024K_8b
• FLASH_512Kx2_8b
• FLASH_512Kx2_16b

The MT1379 permits both 8- and 16-bit common memory I/O accesses with a removable storage card via the host interface.

9.  SERIAL  EEPROM  MEMORY

An I2C serial EEPROM is used to store user configuration (i.e. language preferences, speaker setup, etc.) and software

configuration.. Industry standard EEPROM range in size from 1kbit to 256kbit and share the same IC footprint and pinout. The

default device is 2kbit, 256kx 8, SOIC8 SGS Thomson ST24C02M1 or equivalent.

10. AUDIO INTERFACE AUDIO SAMPLING RATE AND PLL COMPONENT CONFIGURATION

The MT1379 audio mode configuration is selectable, allowing it to interface directly with low-cost audio DACs and ADCs. The

audio port provides a standard I

2

S interface input and output and S/PDIF (IEC958) audio output. Stereo mode is in I

2

S format

while six channels Dolby Digital (5.1 channel) audio output can be channeled through the S/PDIF. The S/PDIF interface consists

of a bi-phase mark encoder, which has low skew. The transmit I

2

S interface supports the 112, 128, 192, 256, 384, and 512

sampling frequency formats, where sampling frequency Fs is usually 32 kHz, 44.1 kHz, 48 kHz, 96 kHz, or 192 kHz. The audio

samples for the I

2

S transmit interface can be 16, 18, 20, 24, and 32-bit samples.

For Linear PCM audio stream format, the MT1379 supports 48 kHz and 96 kHz. Dolby Digital audio only supports 48 kHz. The

MT1379 incorporates a built-in programmable analog PLL in the device architecture in order to generate a master audio clock.

The MCLK pin is for the audio DAC clock and can either be an output from or an input to the MT1379. Audio data out (TSD) and

audio frame sync (TWS) are clocked out of the MT1379 based on the audio transmit bit clock (TBCK). Audio receive bit clock

(RBCK) is used to clock in audio data in (RSD) and audio receive frame sync (RWS).

11. FRONT PANEL

11.1.  VFD  CONTROLLER

The VFD controller is a NEC uPD16311. This controller is not a processor, but does include a simple state machine which

scans the VFD and reads the front panel button matrix. The 16311 also includes RAM so it can store the current state of all

the VFD icons and segments. Therefore, the 16311 need only be accessed when the VFD status changes and when the button

status is read. The MT1379 can control this chip directly using PIO pins or can allow the front panel PIC to control the VFD.

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12.  CONNECTORS

12.1.  SCART  CONNECTORS

Pinout of the scart connector:

1 à Audio Right Out
2 à Audio Right In
3 à Audio Left / Monu Out
4 à Audio Gnd
5 à Blue Gnd
6 à Audio Left / Mono In
7 à Blue
8 à Control Voltage
9 à Green Gnd
10 à Comms Data 2
11 à Green
12 à Comms Data 1
13 à Red Gnd
14 à Comms Data Gnd
15 à Red
16 à Fast Blanking
17 à Video Gnd
18 à Fast Blanking Gnd
19 à Composite Video In
20 à Composite Video Out
21 à Shield

Some cheaper SCART cables use unshielded wires, which is just about acceptable for short cable lengths. For longer lengths,

shielded co-ax cable become essential.

Scart Signals:
Audio signals
0.5V RMS, <1K output impedance, >10K input impedance.
Red, Green, Blue
0.7Vpp ±2dB, 75R input and output impedance. Note that the Red connection (pin 20) can alternatively carry the S-Video

Chrominance signal, which is 0.3V.
Composite Video / CSync
1Vpp including sync, ±2dB, 75R input and output impedance.Bandwidth = 25Hz to 4.8MHz for normal TV Video de-emphasis

to CCIR 405.1 (625-line TV)