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Preliminary User’s Manual U17566EE1V2UM00
Chapter 23 LCD Bus Interface (LCD-I/F)
The LCD Bus Interface connects the internal peripheral bus to an external LCD
controller. It provides an asynchronous 8-bit parallel data bus and two control
lines.
The LCD Bus Interface supports bidirectional communication. You can send
data to and query data from the LCD controller.
23.1 Overview
The LCD Bus Interface transmits or receives data bytes. Two control lines
specify the read/write timing and the transfer direction.
The LCD Bus Interface suits LCD controllers that feature automatic generation
of display memory addresses. The interface does not generate or interpret
specific signals that may be required by the LCD controller, like address, chip
select, hold, and so on. If necessary, such signals can be provided by general
purpose I/Os.
Features summary
The LCD Bus Interface provides:
• Support of two different control signals modes:
– mod80 with separate read and write strobe
– mod68 with read/write signal and data strobe “E” with selectable level
• DMA for read and write operations
• 8/16/32-bit write and read operations
• Programmable transfer speed (100 KHz … 3.2 MHz) through
– selectable clock input
– programmable transfer time
– programmable wait states
• Interrupt generation selectable upon two events
– internal data transfer allowed
– external bus access completed
• Flags that indicate the status of the data register and the progress of data
transfer to or from the LCD controller
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