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User’s Manual for Advantech SOM-A2558 series module V1.00
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2.2.7 SD/MMC
All SOM-A255x series supports 1 slot SD/MMC port. The Multi Media
Card (MMC) is a low cost data storage and communication media. The MMC
controller in the SOM-A255x is compliant with The Multi Media Card System
Specification, Version 2.1. The only exception is one and three byte data
transfers are not supported.
SD/MMC I/F in SOM-A255x only support 1-bit memory mode, not support
I/O mode.
2.2.8 Audio (AC’97 Codec on board)
All SOM-A255x uses Realtek ALC202 AC97 audio Codec on SOM
module. SOM-A255x series provides mono microphone-in, stereo line-in, and
stereo line-out interface. If users want to drive speakers, users could follow the
“Advantech SOM-A255x series CSB design guide “to design the audio
amplifier on CSB.
2.2.9 CRT-out
SOM-A255F & SOM-A2552 series supplies CRT-out I/F which resolution
is up to 1024*768. CRT-out function comes from SM501. CRT-out signals are
all analog signals; user must follow the analog signals layout rules.
SOM-A2558 series doesn’t support CRT-out function, but user could
design CRT-out solution IC on CSB to add the function on SOM-A2558
platform. About detail implement way, please check “Advantech SOM-A255x
series CSB design guide “.
2.2.10 LCD TTL interface w/LCD Brightness & Contrast Control interface
SOM-A2552 & SOM-A255F series LCD-out interface comes from SM501.
SOM-A2552 & SOM-A255F LCD-out supports 24 bit and resolution up to
1024*768. SOM-A2552 & SOM-A255F supports both active and passive LCD
displays. SOM-A2558 series LCD-out function comes from SoC PXA255.
SOM-A2558 LCD-out supports 16 bit and resolution up to 800*600.
The LCD signals are 3.3V level in X2. If users’ CSB want to drive 5V level
panel, users could design buffers on CSB to translate LCD signals level. User
could refer “Advantech SOM-A255x series CSB design guide “.
Advantech design LCD brightness control circuit & LCD contrast control
circuit on SOM-A255x series modules. STN LCD panel needs contrast control
signals. In X2, LCD contrast control signals are nVCONR_INC, VCONR_CS
and VCONR_UnD. The control signals are based on DALLAS DS1804 NV
Trimmer Potentiometer to design. Users could check the “Advantech
SOM-A255x series CSB design guide “ to know how to wire. User could check
“to know how to control.
Brightness control signals are used to control the LCD backlight inverter
lamp current. In X2, LCD brightness control signals are nVBRIR_INC,
VBRIR_CS and nVBRIR_UnD. The control signals are based on DALLAS
DS1804 NV Trimmer Potentiometer to design. Users could check the
“Advantech SOM-A255x series CSB design guide “to know how to wire. User
could check appendix about SOM-A255F memory map to know how to control.