Atmel SAM9X25, Manual

Page: 311 / 1145

311
11054A–ATARM–27-Jul-11
SAM9X25
311
11054A–ATARM–27-Jul-11
SAM9X25
26. External Bus Interface (EBI)
26.1 Description
The External Bus Interface (EBI) is designed to ensure the successful data transfer between
several external devices and the embedded Memory Controller of an ARM-based device.
The Static Memory, DDR, SDRAM and ECC Controllers are all featured external Memory Con-
trollers on the EBI. These external Memory Controllers are capable of handling several types of
external memory and peripheral devices, such as SRAM, PROM, EPROM, EEPROM, Flash,
DDR2 and SDRAM. The EBI operates with 1.8V or 3.3V Power Supply (VDDIOM).
The EBI also supports the NAND Flash protocols via integrated circuitry that greatly reduces the
requirements for external components. Furthermore, the EBI handles data transfers with up to
six external devices, each assigned to six address spaces defined by the embedded Memory
Controller. Data transfers are performed through a 16-bit or 32-bit data bus, an address bus of
up to 26 bits, up to six chip select lines (NCS[5:0]) and several control pins that are generally
multiplexed between the different external Memory Controllers.
26.2 Embedded Characteristics
• Integrates three External Memory Controllers:
– Static Memory Controller
– DDR2/SDRAM Controller
– MLC Nand Flash ECC Controller
• Up to 26-bit Address Bus (up to 64 MBytes linear per chip select)
• Up to 6 chips selects, Configurable Assignment:
– Static Memory Controller on NCS0, NCS1, NCS2, NCS3, NCS4, NCS5
– DDR2/SDRAM Controller (SDCS) or Static Memory Controller on NCS1
– NAND Flash support on NCS3