DEOLP and DILSM disabled out of reset

Michael Sch,

Other Parts Discussed in Thread: TMS570LS3137

Hi,

in the ARM Manual for the Cortex-R4, the two configuration bits DEOLP and DILSM, which are part of the Auxiliary Control Register, should be enabled out of reset.

DEOLP -> 'Disable end of loop prediction'
DILSM -> 'Disable Low Interrupt Latency (LIL) on load/store multiples'

However, in the TMS570LS3137 those two bits are disabled.
Is there any reason for this or is it safe to turn those features on after coming out of a reset?

Kind regards,
Michael

over 10 years ago

0 KGreb over 10 years ago

TI__Mastermind 23000 points

Hi Michael,

ARM establishes the defaults settings of these control bits inside the CPU; TI has no control over this behavior. It may be that ARM has an error in their documentation or that the version of the documentation you are viewing does not match the version of the CPU used in the MCU.

Best Regards,

Karl

0 Michael Sch, over 10 years ago in reply to KGreb

Intellectual 800 points

Hi Karl,

here's the document where I got the information from:

http://infocenter.arm.com/help/topic/com.arm.doc.ddi0363e/Bgbficch.html#Bgbgjdjf

See bits 22..21

Can it be the case, that (as with other settings) these default settings are licensee configurable via dedicated signals inside the SoC?

Kind regards,
Michael

0 KGreb over 10 years ago in reply to Michael Sch,

TI__Mastermind 23000 points

Michael,

The ARM integrator guidelines have no mention of any integration settings impacting these bits.

Regards,

Karl

0 Michael Sch, over 10 years ago in reply to KGreb

Intellectual 800 points

Karl,

thanks anyway. I will then contact ARM directly for getting more information on this issue.

Kind regards,
Michael

0 KGreb over 10 years ago in reply to Michael Sch,

TI__Mastermind 23000 points

Hi Michael,

One of our engineers checked silicon and it is behaving as stated by ARM in the TRM. Both bits are 0x0 after reset. Just to confirm, you are seeing the bits set to 0x1 after reset, correct?

Regards,

Karl

0 Michael Sch, over 10 years ago in reply to KGreb

Intellectual 800 points

Hi Karl,

thanks for the hint. I found now the reason:

There's a mistake in our debugger's register description files. The two bits are zero (= enabled), but the debugger translates it to a "disabled" string. So, it is clearly a problem in the debugger.

Kind regards,
Michael

Arm-based microcontrollers

Arm-based microcontrollers forum

DEOLP and DILSM disabled out of reset