TC333Lp DCACHE Usage as general RAM

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cross mob
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Hello

We are facing memory limitations in our project we use TC333LP and have been exploring options to overcome this issue. One idea we came across is utilizing the DCACHE address range as an extension to our RAM. We found information in the User Manual suggesting that accessing the DCACHE area is possible when the DCACHE is bypassed or disabled.

However, our attempts to use the DCACHE area as additional RAM have been unsuccessful so far. Is it possible to use DCACHE area as an extension to our ram?

Moreover, we stumbled upon another potential solution. We discovered that there is a dedicated RAM called SCR XRAM for the standby controller. We are considering utilizing this RAM as well. Is it possible to use XRAM area as an extension to our ram?

Thanks in Advance.

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MoD
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See in the UM and Appendix register MTU_MEMMAP in chapter Memory Test Unit (MTU). Please note that only PCACHE and DCACHE can be used as ram if they are Memory-mapped. For PTAG and DTAG it is also possible but the Memory-mapped ram can be used only limited.

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MoD
Employee
Employee
50 likes received 500 replies posted 100 solutions authored

See in the UM and Appendix register MTU_MEMMAP in chapter Memory Test Unit (MTU). Please note that only PCACHE and DCACHE can be used as ram if they are Memory-mapped. For PTAG and DTAG it is also possible but the Memory-mapped ram can be used only limited.

formated
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Thanks for your response, it works fine. I'm just having the following questions:

1- it seems that the cache address space is directly after DSPR range. in TC333LP controller DSPR is 192K so the DCACHE will be after follow the DSPR 192K directly. Is my understanding is correct?

2- As we don't use the standby controller. Do you think that SCR XRAM could be utilized as well?

3- Is DTAG ram could be used for CSA (Context Saving Area)? 

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MoD
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50 likes received 500 replies posted 100 solutions authored

1- Yes, your understanding is correct.

2- Yes, it can be used as SRAM (not for CSA), no memory mapping needed.

3- No, the DTAG ram could not be used for CSA. The DTAG ram can be used only as DTAG because it is a specific SRAM.

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