Specifications

39
This range is dedicated to
extender board devices.
LB_DATA_EN - 3V Data enable signal. Derived from
chip select signals. Should be
connected to output enable on the
data buffers.
Local Bus Buffering
The internal local bus of the EM-X270 operates at 1.8V voltage levels. A part of the bus is
level shifted to 3V on the EM-X270 board. The signals available on the extender connector
are partially at the 3V level and partially at the 1.8V level. Voltage level shifting buffering
is needed when the 1.8V signals are used.
The local bus must be used very carefully, as bad routing, overloading or contention
created by off-board circuitry will affect functionality of on-board components as well. As
a general rule, the local bus should be buffered before any further routing or connections
on the baseboard. Buffers should be located near the module's connectors. Buffer reference
design is available in the schematics of the EB-X270.
LCD Controller Bus
The PXA270 LCD controller signals are routed to the extender board connector to allow
custom LCD panels to be interfaced with the EM-X270 board.
The LCD Controller signals are described in section 4.5.
For more information, please see chapter 7 – “LCD Controller” in the PXA270 Reference
Guide. Reference design for LCD bus connection is available in the schematics of the EB-
X270.
Touch Screen Interface
NOTE: only available on EM-X270 – rev1.3 and higher.
The four input signals of the on-board touch screen controller are routed to the extender
board connecter.
EM-X270
Name
Type Description
LCD_TSPX Analogue input Touch-panel input: X+ (Right) for 4-wire
LCD_TSMX Analogue input Touch-panel input: X- (Left) for 4-wire
LCD_TSPY Analogue input Touch-panel input: Y+ (Top) for 4-wire
LCD_TSMY Analogue input Touch-panel input: Y- (Bottom) for 4-wire