nERROR pin and ESM Low-Time Counter Preload Register

Gareth Price

I have tried to write to the ESM Low-Time Counter Preload Register ESMLTCPR while in supervisor mode but the register does not seem to change! Both ESMLTCR and ESMLTCPR have the value 0x3FFF. I would expect this of ESMLTCR but the manual states that ESMLTCPR should have the value 0x1 at reset. Can you tell me how I can write to ESMLTCPR in order to set the value of ESMLTCR.

I require the nERROR pin to be set low for a very short time during eFuse, OTP 2bit ECC and RAM &FLASH 2bit ECC error checking as defined in your manual and initialisation example SPNA106C. After the self tests I then want to configure the nERROR pin to be low for a longer time. In this way my external circuitry can distinguish between internal startup tests and actual errors based on the length of the nERROR pin pulse.

over 12 years ago

0 John Hall over 12 years ago

TI__Genius 9015 points

Hello Gareth,

I have forwarded your question to the expert on this. They will be responding soon.

0 Gareth Price over 12 years ago in reply to John Hall

Prodigy 180 points

Any news yet? Do you require code stubs?

0 Prathap over 12 years ago

TI__Genius 14205 points

1) Sorry for the confusion, It's a typo in the TRM, ESMLTCPR and ESMLTCR default value at reset = 0x3FFF. I will report this to the corresponding team.

2) Suggestion for your Used case

a) Writing "esmREG->KEY = 0xAU;" will take the Error Pin Low immediately. Leave ESMLTCPR default.

b) Write "esmREG->KEY = 0x5U;" will take the Pin to High after the Minimum tError ( (0x3FFF + 1) * tVCLK).

c) Start your Self Test routines.. During this window ( This is minimum possible window) you can perform your SelfChecks.. After the window period Pin goes High and KEY register reset's to 0.

d) Configure ESMLTCPR to higher value ( 0x7FFF, 0xBFFF, 0xFFFF ) so that when Error occurs the Pin stays low for configured tError time.. More over software can control further by delaying the write to the Key ( "esmREG->KEY = 0x5U;") so that Pin stays low as long as software requires.

Hope it helps!

Regards
Prathap

0 Gareth Price over 12 years ago in reply to Prathap

Prodigy 180 points

So am I right in thinking that the minimum time settable for ESMLTCPR is 0x3FFF?

0 Gareth Price over 12 years ago in reply to Gareth Price

Prodigy 180 points

Any news?

0 Henry Nguyen over 12 years ago in reply to Gareth Price

TI__Expert 4225 points

Hi Gareth,

The ESMLTCPR bit 15:14 are the only bits that you can change. Bit 13:0 is default to all 1's and these are read only bits.

If you look at the TRM, the bit 15:14 is denoted as R/W while bit 13:0 denoted as R-1. I agree that it is a little bit confusing, but it is actually all 1's.

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nERROR pin and ESM Low-Time Counter Preload Register