RCW registers are not memory mapped registers.
I assume that RCW is deployed on flash, you could refer to the following procedure to dump flash memory.
$ dd if=/dev/mtd0 of=file bs=512 count=1
b25805@star:~$ xxd file
00000000: 55aa 55aa 0000 1080 1040 003c 3000 0000 U.U......@.<0...
00000010: 0000 0000 0000 0000 0000 0000 0000 8f01 ................
00000020: 00c0 3000 0000 0000 a031 2002 8025 0000 ..0......1 ..%..
00000030: 0000 0000 9632 0000 0000 0000 1000 0000 .....2..........
00000040: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000060: 0000 0000 0000 0000 0000 0000 0000 0000 ................
00000070: 0070 0e00 0000 0000 0000 58bb 0000 0000 .p........X.....
00000080: 0000 0000 0000 0000 5ba4 ac25 9008 4033 ........[..%..@3
00000090: 0104 8000 9008 5033 0104 8000 bc08 4033 ......P3......@3
000000a0: 0100 0000 5401 4033 4747 4747 5801 4033 ....T.@3GGGGX.@3
Thanks,
Yiping