NB2DSK01 - Independent SRAM

The NB2DSK01 also includes independent Static RAM as part of the memory resources available to the NanoTalk Controller, or more specifically the firmware running within. The term 'independent' is used in this case to distinguish this SRAM – which is interfaced using dedicated address and data lines – from the SRAM that is accessed over a common bus (also used to access on-board SDRAM and Flash memory).

Figure 1. Independent SRAM used by the
NB2DSK01's firmware.

The SRAM is provided in the form of two 4Mbit, high-speed CMOS SRAM devices. Each device is organized as 256K x 16 bits – combined together to give 256K x 32-bit storage (1MByte). Both devices are powered by the NB2DSK01's 3.3V supply.

Location on Board

The independent SRAM devices (designated U22 and U23) are located on the component side of the board, to the right of the NanoTalk Controller (U5) and within the real estate that falls beneath the TFT LCD panel.

Schematic Reference

The independent SRAM devices can be found on Sheet 41 (SRAM_256Kx32_TSOP44_2.SchDoc, entitled 256K x 32 SRAM - TSOP44 x 2) of the motherboard schematics.