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Memory Interfaces Overview
3.2Memory Interfaces Overview
This section describes the different memory interfaces of DM643x DMP. The DM643x DMP supports several memory and external device interfaces, including the following:
∙DDR2 synchronous DRAM
∙Asynchronous EMIF/NOR/NAND Flash
3.2.1 DDR2 External Memory Interface
The DDR2 external memory interface (EMIF) port is a dedicated interface to DDR2 SDRAM. It supports
DDR2 SDRAM plays a key role in a DM643x
∙Buffering input image data from sensors or video sources
∙Intermediate buffering for processing/resizing of image data in the video processing front end (VPFE)
∙Video processing back end (VPBE) display buffers
∙Intermediate buffering for large raw Bayer data image files while performing still camera processing functions
∙Buffering for intermediate data while performing video encode and decode functions
∙Storage of executable firmware for DSP
3.2.2External Memory Interface
The DM643x DMP external memory interface (EMIF) provides an
The EMIFA signals are multiplexed with other peripheral signals on the device. Refer to
3.2.2.1Asynchronous EMIF Interface
The asynchronous EMIF (EMIFA) interface provides both the asynchronous EMIF and NAND interfaces. Four chip selects are provided. Each is individually configurable to provide either asynchronous EMIF or NAND support.
∙The asynchronous EMIF mode supports asynchronous devices (RAM, ROM, and NOR Flash)
∙64MB asynchronous address range over 4 chip selects (16MB each)
∙Supports
∙Programmable asynchronous cycle timings
∙Supports extended waits
∙Supports Select Strobe mode
∙Supports TI DSP HPI interface
∙Supports booting DM643x DMP from CS2 (SRAM/NOR Flash)
3.2.2.2NAND Interface
The asynchronous EMIF (EMIFA) interface provides both the asynchronous EMIF and NAND interfaces. Four chip selects are provided and each is individually configurable to provide either EMIFA or NAND support.
∙The NAND mode supports NAND Flash on up to 4 asynchronous chip selects
∙Supports
∙Programmable cycle timings
∙Performs ECC calculation
∙Bootloader code in Boot ROM supports booting of the DM643x DMP from
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