SED1374 Datasheet, PDF (403/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

EPSON Research and Development
Vancouver Design Center
Page 13
4.2.2 Standard Epson LCD Connector, J4
A shrouded 40-pin header, J4, is also added to the CPU module to connect to LCD panels.
This header is the standard LCD connector used on Epson Research and Development
evaluation boards and can be used to directly connect LCD panels to the SED1374/75
controller. All LCD signals are buffered to allow 3.3V or 5.0V logic LCD panels to be
connected. Jumper, JP9, selects between these two types of panels.
A positive power supply for panels requiring a positive bias voltage is supplied to header
J4, by the LCD module through the 50-pin LCD module connector, J3. No negative power
supply is available on the LCD module, therefore only panels which have their own bias
voltage supply, or those that use a positive supply, can be connected to J4. The LCD
module can only support these panels as well.
Header, J4, and its associated buffers and components have been left unpopulated on the
CPU module. These parts can be added by the user if desired.
4.3 LCD Controller
4.3.1 SED1374 vs. SED1375
The LCD controller used in conjunction with the TMPR3912/22U microprocessor can
either be a SED1374 or a SED1375. If a SED1374 is used, jumper JP7 must be set to
position 1 2. This setting allows CNF4 to be configured for the SED1374. CNF4 controls
the polarity of the LCDPWR signal and can be set either high or low with jumper, JP11. If
a SED1375 is used, jumper JP7 must be set to position 2 3. This setting allows pin 45 of
the LCDC to be used as address bit, AB16, which is needed on the SED1375 to accom-
modate the larger display memory.
4.3.2 LCDPWR Polarity
The power supply on the LCD module used LCDON, an active low signal to turn on the
supply. This signal is connected to LCDPWR. Since LCDPWR is configurable on the
SED1374 and is set active high on the SED1375, a facility must be provided to invert this
signal if it is active high so that LCDON will be the right polarity to turn on the LCD power
supply. Jumper, JP10 must be set to position 1 2 if LCDPWR is active low and to position
2 3 if LCDPWR is active high.
4.3.3 SED1374\75 Chip Select
Minimal glue logic is used on the CPU module to provide the chip select signal, CS#, for
the LCDC. A simple AND gate activates the SED1374/75 whenever the PC Card slot #1
is accessed, whether it be memory space or attribute space.
SDU1374/75-TMPR3912/22U CPU Module
Issue Date: 98/12/23
X00A-G-004-01