Hi,
I'm just writing a new bootloader for the LPC2148 and was wondering what
you guys recommend as far as the MAMTIM & MAMCR values should be for best
reliability/repeatability.
The LPC2148 errata states the accelerator SHOULD be enabled but I'm a
little confused at whether to use a partial or fully enabled accelerator.
The errata first states it should be fully enable, then goes onto to say a fully
enabled accelerator 'may' cause problems (depending on code location
and type of code).
The LPC2148 has a 12MHz xtal and I'm currently setting the cclk and pclk to
60MHz.
I'm currently fully enabling the memory accelerator (MAMCR = 2) with 3 cclk
clocks (MAMTIM = 3) ... all works ok with the LPC2148 chip I have here.
I don't use interrupts at all in the bootloader and blowing new user
firmware from a file off SD card, done it many many times without a single error
(so far).
Thanks for any suggestions.
C.
LPC2148 Mam Timing
Started by ●October 15, 2009
Reply by ●October 15, 20092009-10-15
I never had any issues with that. Which silicon revision is the errata
about?
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 cm296pip
>
> Hi,
>
> I'm just writing a new bootloader for the LPC2148 and was wondering what
> you guys recommend as far as the MAMTIM & MAMCR values should be for best
> reliability/repeatability.
>
> The LPC2148 errata states the accelerator SHOULD be enabled but I'm a
> little confused at whether to use a partial or fully enabled accelerator.
>
> The errata first states it should be fully enable, then goes onto to say a
> fully enabled accelerator 'may' cause problems (depending on code location
> and type of code).
>
> The LPC2148 has a 12MHz xtal and I'm currently setting the cclk and pclk to
> 60MHz.
>
> I'm currently fully enabling the memory accelerator (MAMCR = 2) with 3 cclk
> clocks (MAMTIM = 3) ... all works ok with the LPC2148 chip I have here.
>
> I don't use interrupts at all in the bootloader and blowing new user
> firmware from a file off SD card, done it many many times without a single
> error (so far).
>
> Thanks for any suggestions.
>
> C.
>
>
>
about?
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 cm296pip
>
> Hi,
>
> I'm just writing a new bootloader for the LPC2148 and was wondering what
> you guys recommend as far as the MAMTIM & MAMCR values should be for best
> reliability/repeatability.
>
> The LPC2148 errata states the accelerator SHOULD be enabled but I'm a
> little confused at whether to use a partial or fully enabled accelerator.
>
> The errata first states it should be fully enable, then goes onto to say a
> fully enabled accelerator 'may' cause problems (depending on code location
> and type of code).
>
> The LPC2148 has a 12MHz xtal and I'm currently setting the cclk and pclk to
> 60MHz.
>
> I'm currently fully enabling the memory accelerator (MAMCR = 2) with 3 cclk
> clocks (MAMTIM = 3) ... all works ok with the LPC2148 chip I have here.
>
> I don't use interrupts at all in the bootloader and blowing new user
> firmware from a file off SD card, done it many many times without a single
> error (so far).
>
> Thanks for any suggestions.
>
> C.
>
>
>
Reply by ●October 15, 20092009-10-15
> I never had any issues with that. Which silicon
revision is the errata
> about?
2nd attempt at replying .. pesky yahoo.
If no one has had an issue with the MAM problems then I'll leave things as is.
The last errata I can find on the nxp site is this one ..
.. from this list ..
MAM.1 problem .. rev '-' chips. (the chip I have here)
MAM.2 problem .. rev '-' & 'A' chips.
Thanks for the reply anyway.
> about?
2nd attempt at replying .. pesky yahoo.
If no one has had an issue with the MAM problems then I'll leave things as is.
The last errata I can find on the nxp site is this one ..
.. from this list ..
MAM.1 problem .. rev '-' chips. (the chip I have here)
MAM.2 problem .. rev '-' & 'A' chips.
Thanks for the reply anyway.
Reply by ●October 15, 20092009-10-15
I never noticed a problem because of this, I'm using "A" parts, but, if
it's
forsame critical/safety application I wouldn't go with parts <"B" as they
don't specify exactly when does that fail happen.
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 cm296pip
>
> > I never had any issues with that. Which silicon revision is the errata
> > about?
>
> 2nd attempt at replying .. pesky yahoo.
>
> If no one has had an issue with the MAM problems then I'll leave things as
> is.
>
> The last errata I can find on the nxp site is this one ..
>
> <
> http://www.standardics.nxp.com/support/documents/microcontrollers/pdf/errata.lpc2148.pdf
> > .. from this list ..
>
> MAM.1 problem .. rev '-' chips. (the chip I have here)
> MAM.2 problem .. rev '-' & 'A' chips.
>
> Thanks for the reply anyway.
>
>
>
forsame critical/safety application I wouldn't go with parts <"B" as they
don't specify exactly when does that fail happen.
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 cm296pip
>
> > I never had any issues with that. Which silicon revision is the errata
> > about?
>
> 2nd attempt at replying .. pesky yahoo.
>
> If no one has had an issue with the MAM problems then I'll leave things as
> is.
>
> The last errata I can find on the nxp site is this one ..
>
> <
> http://www.standardics.nxp.com/support/documents/microcontrollers/pdf/errata.lpc2148.pdf
> > .. from this list ..
>
> MAM.1 problem .. rev '-' chips. (the chip I have here)
> MAM.2 problem .. rev '-' & 'A' chips.
>
> Thanks for the reply anyway.
>
>
>
Reply by ●October 15, 20092009-10-15
Hi C.
I have been using "-", "A" and "B" parts for a while. I have found MAM.1 and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236 and others).
After dealing with inconsistent problem occurrences, I decide to use the following configuration which (in my own experience) is totally safe (for my application):
* CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC speed)
* MAM FULL (Mode 2)
* MAMTIM = 4
At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A" and some "B") working full-time without any MAM issue.
Cheers and good luck!
Gaspar
I have been using "-", "A" and "B" parts for a while. I have found MAM.1 and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236 and others).
After dealing with inconsistent problem occurrences, I decide to use the following configuration which (in my own experience) is totally safe (for my application):
* CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC speed)
* MAM FULL (Mode 2)
* MAMTIM = 4
At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A" and some "B") working full-time without any MAM issue.
Cheers and good luck!
Gaspar
Reply by ●October 15, 20092009-10-15
Hi Gaspar,
Thank you for that Information, I never had a problem with this chips,
but I must
confess that I always were quite under the temp specs, I will be using some
LPC21xx
chips in an application where safety is more important so I will go with the
48Mhz "fix".
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 gasparpollano
> Hi C.
>
> I have been using "-", "A" and "B" parts for a while. I have found MAM.1
> and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236
> and others).
>
> After dealing with inconsistent problem occurrences, I decide to use the
> following configuration which (in my own experience) is totally safe (for my
> application):
>
> * CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC
> speed)
>
> * MAM FULL (Mode 2)
>
> * MAMTIM = 4
>
> At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A"
> and some "B") working full-time without any MAM issue.
>
> Cheers and good luck!
>
> Gaspar
>
>
>
Thank you for that Information, I never had a problem with this chips,
but I must
confess that I always were quite under the temp specs, I will be using some
LPC21xx
chips in an application where safety is more important so I will go with the
48Mhz "fix".
Miguel Angel Ajo Pelayo
http://www.nbee.es
+34 91 120 1798
+34 636 52 25 69
skype: ajoajoajo
2009/10/15 gasparpollano
> Hi C.
>
> I have been using "-", "A" and "B" parts for a while. I have found MAM.1
> and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236
> and others).
>
> After dealing with inconsistent problem occurrences, I decide to use the
> following configuration which (in my own experience) is totally safe (for my
> application):
>
> * CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC
> speed)
>
> * MAM FULL (Mode 2)
>
> * MAMTIM = 4
>
> At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A"
> and some "B") working full-time without any MAM issue.
>
> Cheers and good luck!
>
> Gaspar
>
>
>
Reply by ●October 15, 20092009-10-15
Hi Gaspar,
> I have been using "-", "A" and "B" parts for a while. I have found MAM.1 and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236 and others).
>
> After dealing with inconsistent problem occurrences, I decide to use the following configuration which (in my own experience) is totally safe (for my application):
>
> * CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC speed)
>
> * MAM FULL (Mode 2)
>
> * MAMTIM = 4
>
> At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A" and some "B") working full-time without any MAM issue.
>
> Cheers and good luck!
In that case I shall do the same.
Thank you for your reply and thank you for letting me know!
60MHz would be nice but if it's caused a problem then that's a no no (I'm doing DSP with the little chip).
C.
> I have been using "-", "A" and "B" parts for a while. I have found MAM.1 and MAM.2 problems in "-" y "A" parts (see messages #28222,#28274, #28236 and others).
>
> After dealing with inconsistent problem occurrences, I decide to use the following configuration which (in my own experience) is totally safe (for my application):
>
> * CLOCK = 48Mhz (from XTAL of 12Mhz. My application is not sensible to uC speed)
>
> * MAM FULL (Mode 2)
>
> * MAMTIM = 4
>
> At moment, there are almost 20 boards with LPC2148 uCs (versions "-", "A" and some "B") working full-time without any MAM issue.
>
> Cheers and good luck!
In that case I shall do the same.
Thank you for your reply and thank you for letting me know!
60MHz would be nice but if it's caused a problem then that's a no no (I'm doing DSP with the little chip).
C.
