User manual

LPC3250 Developer’s Kit v2 - User’s Guide
Page 39
Copyright 2013 © Embedded Artists AB
4.24 SP14: LCD Expansion Interface
The board contains a buffered LCD expansion interface via a 50 pos IDC connector. The expansion
interface also includes UART (see UART multiplexing), I2C and SPI interfaces. These additional
interfaces are for identifying external displays (via configuration I2C-E2PROM) as well as touch screen
controllers. An external LCD pixel clock can also be supplied via the expansion connector.
The LCD expansion connector carries 18 data bits per pixel by default. (6 per RGB color). The
LPC3250 LCD controller can produce 24 data bits per pixel and it is possible to output all these signals
on the LCD expansion connector. The trade-off is that the UART and I2C serial interfaces have to be
removed. Via SJ6-SJ11 it is possible to select what signals to make available on the LCD expansion
connector. By default pad 1-2 are connected on SJ6-SJ11.
On rev B of the OEM base board, JP34 has been added to support the LPC3250 OEM board. JP34
shall be in position 2-3 to route signal LCD_VD18 properly. On the generic schematic this signal is
called LCD_VD3 but for the LPC3250 it is LCD_VD18. The reason for this is for backward compatibility
with previous OEM board designs. Note that the default setting for JP34 is 1-2 and not 2-3, which
it should be for LPC3250.
For performance reasons (on the LPC3250), a system with 16-bit color information per pixel is typically
what is implemented.
See picture below for locating relevant components. The table below lists signal connections.
Figure 23 – LCD Expansion Interface
Signals
LPC3250
I2C-SDA
I2C1-SDA
I2C-SCL
I2C1-SCL
LCD_UART_RXD
U1_RX via multiplexor, UART#1 is used
LCD_UART_TXD
U1_TX via multiplexor, UART#1 is used
BSPI_SCK
SPI1_CLK
BSPI_MOSI
SPI1_DATIO
GPIO31
SPI1_DATIN
GPIO30
GPO_04
GPIO33
GPO_05
GPIO34
GPO_11
LCD Expansion Connector
J26
Expansion Connector Options
Left-to-right:
SJ11, SJ6, SJ10, SJ7, SJ8, SJ9
Expansion Connector
JP21
Jumper
JP34