EFM32WG Datasheet, PDF (173/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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14 EBI - External Bus Interface
0123 4
EBI
( EFM3 2 )
Parallel Int erface
Ext ernal
Asy n c.
Device
14.1 Introduction
What?
Quick Facts
The EBI is used for accessing external
parallel devices. The devices appear as a
part of the EFM32WG's internal memory map
and are therefore extremely simple to use.
Why?
Even though the EFM32WG is versatile,
there might be a need for specific external
devices such as extra RAM, FLASH, LCD,
TFT. The EBI simplifies the access to such
devices.
How?
Through memory mapping the devices
appear as a part of the internal memory map.
When the processor performs read or writes
to the address range of the EBI, the EBI
handles the data transfers to and from the
external devices. The EBI may be interfaced
by the DMA, thus enabling operation in EM1.
The External Bus Interface provides access to external parallel interface devices such as SRAM, FLASH,
ADCs and LCDs. The interface is memory mapped into the address bus of the Cortex-M4. This enables
seamless access from software without manually manipulating the IO settings each time a read or write
is performed. The data and address lines can be multiplexed in order to reduce the number of pins
required to interface the external devices. The bus timing is adjustable to meet specifications of the
external devices. The interface is limited to asynchronous devices and TFT.
14.2 Features
• Programmable interface for various memory types
• 4 memory bank regions
• Individual chip select line (EBI_CSn) per memory bank
• Accurate control of setup, strobe, hold and turn-around timing per memory bank
• Individual active high / active low setting of interface control signals per memory bank
• Slave read/write cycle extension per memory bank
• Page mode read
• NAND Flash support
• Both multiplexed and non-multiplexed address and data line configurations
• Up to 28 address lines
• Up to 16-bit data bus width
• Automatic translation when AHB transaction width and memory width differ
• Configurable prefetch from external device
• Write buffer to limit stalling of the Cortex-M4 or DMA
• TFT Direct Drive
• Programmable display and porch sizes
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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