F28M35 SRAM HB16 NO-MUXED mode question

Hello:

                I use   F28M35H52C1 Silicon Rev B   Chip    work in  HB16 NO-MUXED  Mode  .Now I marked  circuit board  , according to Technical Reference  to set parameter ,but F28M35 don't  access  visit SRAM。

Mode :  HB16 NO-MUXED  

              CSCFGEXT+CSCFG = 0x07.

can't access  SRAM

Mode：   HB8 NO-MUXED

              work ok ,but I  need  iRDY  signal.

               pls  help me，think you！