NanoBoard 3000 - Host Controller SRAM
The NanoBoard 3000 includes independent Static RAM for use by the NanoTalk Controller, or more specifically the firmware running within. This is dedicated SRAM that is separate from the independant and common-bus SRAM made available to the User FPGA.
Independent SRAM used by the
NanoBoard 3000's firmware.
The SRAM is provided in the form of a single 4Mbit, high-speed CMOS SRAM device. Organized as 256K x 16 bits and powered by the motherboard's 3.3V supply, the device gives total storage space of 512KByte.
Although the device requires 18 address lines (SRAM_A[17..0]), the interface makes provision for a nineteenth address line (SRAM_A18), giving the flexibility to accommodate a 512 x 16-bit device, should it require to be fitted.
The embedded software for the Host Controller FPGA is loaded into this memory, once the Controller is configured with the Primary boot image of the NanoBoard firmware.
Location on Board
The independent SRAM device (designated U47) is located on the component side of the board, to the top-right of the Host Controller FPGA (U30) and above the 'PWR' and 'PGM' LEDs for the User FPGA.
Schematic Reference
The independent SRAM device can be found on Sheet 29 (SRAM_256Kx16_TSOP44.SchDoc, entitled 256K x 16-Bit SRAM) of the motherboard schematics.