Hi,
Yes, you can use this address as the flash swap indicator address. For a 1 Meg part, the two 512K halves swap. So the lower half (blocks 0 & 1) will have one flash swap indicator and the upper half (blocks 2 & 3) will have the other flash swap indicator. The location is the same offset from the base of each half. The location is set by feeding in an address in the initialization option of the swap command.