CHAPTER 13 GENERAL PURPOSE I/O UNIT (GIU)
User’s Manual U14272EJ3V0UM
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13.2.3 LCD interface
The GIU supports two functions for the LCD interface. The first is pin mapping for 8-bit STN color LCD panel
support. The second is pin mapping for support of an external LCD controller with integrated frame buffer RAM.
For additional details about the LCD registers, see CHAPTER 21 LCD CONTROLLER.
(1) STN color LCD interface pin mapping
The color LCD panel interface is enabled by writing to the GPIO Mode registers and utilizes the following GPIO
pins:
Table 13-8. STN Color LCD Interface Signals
GPIO pin
LCD signal
Type
GPIO(15:12)
FPD(7:4)
Output
(2) External LCD controller pin mapping
An interface to an external LCD controller can be configured by setting the LCDGPEN bit of the LCDGPMODE
register to 1. In this mode the following internal LCD controller pins are redefined to support the external LCD
controller interface:
Table 13-9. External LCD Controller Interface Signals
LCD pin
External LCD controller interface signal
Type
SHCLK
LCDCS#
Output
LOCLK
MEMCS16#
Input
VPLCD
General-purpose output (VPGPIO1)
Output
VPBIAS
General-purpose output (VPGPIO0)
Output
The LCDCS# output is generated by the address decode logic in the GIU. The address range can be specified
by programming the LCDGPMODE register. The following address ranges are supported:
(1) 0x1338 0000 to 0x133F FFFF (512KB)
(2) 0x133C 0000 to 0x133F FFFF (256KB)
(3) 0x133E 0000 to 0x133F FFFF (128KB)
(4) 0x130A 0000 to 0x130A FFFF (64KB, the address space of the PC/AT
TM
is assumed)
Remark
All memory cycles that access the external LCD controller address space are treated as 16-bit
cycles.
The MEMCS16# input is provided to support external memory devices (besides the external LCD controller)
which need accesses in 16-bit cycles. During an external memory cycle, if the MEMCS16# input is enabled and
asserted, the ISA bridge will generate a 16-bit cycle.