Documentation:AVR32 Datasheet Clarifications
From AVRFreaks Wiki
Contents |
[edit] Introduction
This summarizes commonly asked questions regarding how to connect the AVR32 family devices to external components.
[edit] The EBI bus
The External Bus Interface is where you'll connect memory mapped peripheral to the AVR32. This might be external RAM (FLASH,SRAM,SDRAM), Compact Flash or other (I.E. USB host controller)
The EBI supports 8, 16 and 32 bit data access and is mainly controlled by to units in the AVR32: SMC for static devices and SDRAMC for SDRAM.
[edit] SDRAMC
SDRAM devices can have 16 or 32 bit data bus. In opposition to the SMC controller, the address lines for SDRAMC is always mapped SDRAMC_A12:0 <=> SDRAM_A12:0. For mapping of SDRAMC_A to EBI / device pins see Table 16-2 and Table 16-4 in the AT32AP7000 datasheet.
The selection of 16 or 32 bit data bus is done in the SDRAMC Configuration Register, bit DBW.
[edit] SMC
Static memory devices (SRAM, flash, other ICs) can have 8, 16 or 32 bit data bus. The mapping between device address pins and EBI address pins differs with the data bus width according to Table 16-3 in the AT32AP7000 datasheet.
