Change the space size of PEX IO in README
diff --git a/doc/README.mpc8641hpcn b/doc/README.mpc8641hpcn
index 907a911..8ea0b1e 100644
--- a/doc/README.mpc8641hpcn
+++ b/doc/README.mpc8641hpcn
@@ -117,7 +117,7 @@
0xf800_0000 0xf80f_ffff CCSR 1M
0xf810_0000 0xf81f_ffff PIXIS 1M
0xf840_0000 0xf840_3fff Stack space 32K
- 0xe200_0000 0xe2ff_ffff PCI1/PEX1 IO 512M
- 0xe300_0000 0xe3ff_ffff PCI2/PEX2 IO 512M
+ 0xe200_0000 0xe2ff_ffff PCI1/PEX1 IO 16M
+ 0xe300_0000 0xe3ff_ffff PCI2/PEX2 IO 16M
0xfe00_0000 0xfeff_ffff Flash(alternate)16M
0xff00_0000 0xffff_ffff Flash(boot bank)16M