MPC5774P Out of near RAM

[latheef]

Hi,

We are out of  RAM (64k)  and now when I move some of the OS task stack to System Ram (384K) its affecting the performance of the system. Please let me know how to proceed with this.

Will Enabling the Data Cache for System Ram help? If so please let me know how to do it?

[latheef]

@davidtosenovjan  and all,

I am trying to enable the D cache in MPC5774P (Core e200 z425). But when I refer the core manual it says D Cache not present in e200z4 but the mpc5774p say its present. Please enlighten me. 

Also my requirement for D-cache(if present)is as below:

1)  Dont enable the D-cache for D-mem (starting at 0x5080000) as it access is as fast as cashe but better (no cache miss)

2) Enable the D-cache only for SRAM @ 0x40000000 but with exception for calibration variable at the 0x40000000 - 0x40001000. So  out of 0x40000000, only 0x40001000 - end should be cached.

Please let me know how to proceed on this. 

Thanks,

[petervlna]

Hello,

1) Dont enable the D-cache for D-mem (starting at 0x5080000) as it access is as fast as cashe but better (no cache miss)

Well, this makes no sense.

2) Enable the D-cache only for SRAM @ 0x40000000 but with exception for calibration variable at the 0x40000000 - 0x40001000. So out of 0x40000000, only 0x40001000 - end should be cached.

For enabling Data cache, you will need to set SMPU.

1. define range you want to cover by cache in WORD registers.

In SMPU_RGDn_WORD3 you will enable cache for that particular address range:

Define in word 2 type of cache to be enabled:

2. Enable cache in L1CSRx registers.

Best regards,

Peter

[petervlna]

Hello,

I am trying to enable the D cache in MPC5774P (Core e200 z425). But when I refer the core manual it says D Cache not present in e200z4 but the mpc5774p say its present. Please enlighten me.

Generally for z4 not. But MPC5744P use version Zen z4251n3

Best regards,
Peter