Two ways to start arm (NAND FLASH. NOR FLASH)

Why are there two ways to start?

This is determined by the different characteristics of two types of flash.

NAND flash capacity is large, the cost of storing the unit bit data is much lower, but to read and write to NAND flash according to the specific timing, so the CPU can not directly address the NAND flash data, CPU to NAND flash data read and write through the special NAND flash controller, so NAND flash is more suitable for storing data.

Nor flash capacity of small, fast, nor flash to read and write, input address, and then give read and write signals to get data from the data bus, but the price is higher than NAND flash so suitable for the program memory.

In summary, NOR Flash can be connected directly to the arm's bus, but Dand Flash needs to be connected to the S3S2440 via NAND flash controller.

Two ways to start arm (NAND FLASH. NOR FLASH)