2.3. Memory

2.3.1. EEPROM
2.3.2. NAND boot flash
2.3.3. SDRAM

2.3.1. EEPROM

There is provision for a single EEPROM connected via the I2C bus. All specification boards have an 8KBit (1KB) device fitted as standard but up to 256KBit can be accommodated. The EEPROM is a seven bit addressed device at location 0xA0. The device is typically used to hold the non volatile settings in the ABLE bootloader.

2.3.2. NAND boot flash

The IM2440D20 has provision for a single NAND flash device. This device typically contains the bootloader and JFFS2 filesystem with a Linux image to boot, though it can contain anything the user requires. The flash is implemented as a single device, which is connected using the processors NAND bus.

Figure 2.2. NAND flash to S3C2440 attachment

NAND flash to S3C2440 attachment

2.3.3. SDRAM

The IM2440D20 has provision for two or four SDRAM device with up to 512MBit capacity. Typically four 256MBit devices are fitted giving 128MBytes of storage. This memory is accessed using the integrated S3c2440 SDRAM controller.

Figure 2.3. SDRAM to S3C24440 attachment

SDRAM to S3C24440 attachment