# NOEL-V XLEN 64 bits with AHB 32 bits
**URL:** https://discourse.grlib.community/t/noel-v-xlen-64-bits-with-ahb-32-bits/498
**Category:** NOEL-V
**Created:** [10 April 2025 11:59 UTC](https://discourse.grlib.community/t/noel-v-xlen-64-bits-with-ahb-32-bits/498 "2025-04-10T11:59:48Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Lucas\_Elsys\_Design](https://discourse.grlib.community/u/Lucas_Elsys_Design)
#### Post date: [10 April 2025 11:59 UTC](https://discourse.grlib.community/t/noel-v-xlen-64-bits-with-ahb-32-bits/498/1 "2025-04-10T11:59:48Z")
Hello,
Into our design we have configure NOEL-V processor with XLEN = 64 (configuration CFG\_NOELV\_XLEN = 64)
We would like to have the internal AHB size to 32 bits length (configuration of CFG\_AHBDW=64)
In this configuration the ISA test suite and 64bits instructions in general are not working. This is normal ? We haven’t found into the library documentation a clear sentence about that.
Thank you for your reply.
Regards,
Lucas
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### Author:  [@joaquin.espana](https://discourse.grlib.community/u/joaquin.espana)
#### Post date: [17 April 2025 11:09 UTC](https://discourse.grlib.community/t/noel-v-xlen-64-bits-with-ahb-32-bits/498/2 "2025-04-17T11:09:43Z")
Hi Lucas,
I am not sure if I follow. The AHB size is set to 64 bits according to the constants, but you mentioned 32. Which one is correct? Relevant text below:
“We would like to have the internal AHB size to 32 bits length (configuration of CFG\_AHBDW=64)”
Joaquin
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### Author:  [@Lucas\_Elsys\_Design](https://discourse.grlib.community/u/Lucas_Elsys_Design)
#### Post date: [17 April 2025 13:23 UTC](https://discourse.grlib.community/t/noel-v-xlen-64-bits-with-ahb-32-bits/498/3 "2025-04-17T13:23:18Z")
Hello,
You are right i have made a mistake.
My configuration is AHB 32 bits =\> CFG\_AHBDW=32
My CPU XLEN is set to 64 with CFG\_NOELV\_XLEN = 64
For this configuration it doesn’t work. Is it normal ? Do we have to make some others configuration ?
Thank you for your reply.
Best Regards,
Lucas