Circuit Descriptions, List of Abbreviations and IC DataSD-49.EN 47
External Memorythe other three channels (pins 32, 33 and 34) are Y, C, and
The STi55xx family is capable of accessing external memory CVBS.
via three buses:A new video output buffer (see diagram M7, e.g. item 7707 for
The enhanced memory interface (EMI). This interface is R) is implemented: an 8MHz/16MHz selectable filter stage and
configurable and can be used to access Flash, ROM, and a 75& drive stage.
various flavours of DRAM. The EMI is connected to:
- Flash/ROM in Bank 3 (item 7410 and 7401 optional). Miscellaneous I/O Signals
This memory holds the DVD firmware, and is controlled Most general IO ports are connected directly to the module
by pin 186 (FLASH_OE) of the STi5580. It must be interface. Compared with the SD3.0 module, some on-board
able to perform a download (by disk or DCU ) in a circuits are removed, as it made more sense (and more cost
Flash-only system.effective) to implement these circuits externally.
- SDRAM in Bank 0 (item 7402, optional). A 64Mbits (4M
x 16bits) 7.5ns SDRAM can be connected to the EMI
SCART
when the module is used as a Software Development
Previously, an on-board circuit switches the 0|6|12V signal to
Module (SDM).
the correct voltage level. This circuit is removed, and instead,
The shared memory interface (SMI). The SMI is only
the SCART0 and SCART1 signals are now directly available at
capable of accessing SDRAM. The SMI is connected to a
the module interface.
64Mbits (4M x 16bit) 7.5ns SDRAM (item 7500). There is
no longer the option to use two pieces of 16Mbits SDRAM.
Mute
The SDRAM has the following functions:
Previously, an on-board circuit provides the driving current for
- It is used by the MPEG video decoder as a frame
the muting transistors, as well as maintains the correct time
buffer.
delay (to prevent switching noise). This circuit is removed.
- It holds the software and the variables used by it.
Instead, the MUTE signal is now directly available at the
The I2C bus. Via this bus, the NVRAM (or EEPROM) is
module interface.
accessible. This memory is used to store user settings,
player settings, and region code.
Service
Note: The I2C controller PCF8584T is not longer used in the
SD4.0.Service Port Buffer
5V
Audio Output
The audio interfaces available in SD4.0 are I2S and S/PDIF for
digital audio output, and I2S karaoke microphone input.
1k
100R
I2S audioOut4k
TXD_SER
The STi55xx is capable of 6-channel I2S output. These
channels can be configured to output 5.1 Dolby Digital, DTS,
1n54k
etc.
PCM_OUT0: left and right.
PCM_OUT1: centre and LFE.3V3
PCM_OUT2: left and right surround.
Two additional channels (available in STi5580 and STi5588)
10k
are capable of providing down-mixed stereo.
RXD_SER
10k
In
S/PDIF
The S/PDIF signal level (item 7600, pin 57, SPDIF_OUT) is 5V
10k
TTL at module interface. To meet the complete S/PDIF
6k8
specifications, an external de-coupling circuit (item 7716,
diagram M7) is implemented.CL 16532163_049.eps
230102
I2S karaoke (optional)
The STi5580 and STi5588 have built-in karaoke processing. Figure 9-3
The internal karaoke block accepts I2S signal, acting as the
master by generating the required KOKPCMCLK frequency.
The service port (see diagram M5) is simplified to reduce cost.
This frequency is always 1/4 the music sampling frequency.
The unused RTS and CTS lines are no longer connected. A
An external analogue-to-digital converter (ADC), acting as
transistor buffer (item 7502) is used instead of the Schmitt
slave, is required to convert the microphone signals to I2S Trigger buffer.
signals.
The overall loading and driving capability of the RS-232
emulator port is not greatly changed. However, as a
Video Outputprecaution, the Schmitt Trigger circuit remains in the layout as
an optional implementation.
Digital video (optional)
Digital YUV output is routed directly from STi55xx ports to a 22-5V buffers
pin connector (item 1703). From the same connector, the Previously, some IO lines (centre_on and kar_bypass) are
HSYNC, VSYNC and 27MHZ_CLK signals are available. The buffered from 3.3V to 5V. These buffers are removed.
digital YUV connector is the interface to external video Therefore, the signal levels at the module interface are 3.3V
processing devices, such as high quality progressive scan only.
codex and high quality video DAC.Note: Care must be taken that the external circuitry does not
force any IO line from the module to more than 3.8V.
Analogue video
The STi55xx is capable of 6-channel analogue video. Three External DAC
channels (pins 25, 26 and 27) are RGB or YUV format, while In the fourth DVD player generation (VFM2002), a new external
audio DAC from AKM (AK4382) is used. |
ACEC
PHILIPS
