P0.31 is connected to nothing. It is a output only pin with internal pullup by
definition, that should not be pulled low.
--- In l..., "Charles R. Grenz" wrote:
> gmpundlik wrote:
> > Hello,
> >
> > I further rechecked the schematic and the tested the boards again.
> >
> > The schematic is good, reset circuit has a 10K pullup and 0.1uF capacitor to
the ground. P0.14 has a 10K pullup and jumper to the ground. There are in all 36
pins used for I/O. Pin P0.31 is left open and not used, so it should not pose
any problem. I also changed the crystal from a KDS make that had no datasheet,
to a Vishay crystal of known parameters, 20pF load capacitance so that the 33pF
capacitors matched.
> >
> > Voltages on all power pins are OK. I scoped the serial port signals and
traced with a serial port monitor. The '?' command is being sent, but
there is no response from the microcontroller. The clock shows low on one pin
and high on the other.
> >
> > Pin P1.20 when low is supposed to put pins P16:25 in traceport mode, so I
set it to high by a jumper. Pin P1.26 (enables JTAG when low) is also not used,
left unconnected.
> >
> > I have probably checked for every possible pin that could send the LPC2132
into some other mode and prevent it from responding to ISP.
> >
> > I had used a LPC2114 earlier in this project, that had no problem doing ISP
right at first power up. I am sure LPC2132 is no different. At least, I did not
find any ISP related cases other than bad handling of P0.14 or other hardware
errors.
> >
> > Now, is there anything else I could be missing, in terms of logic levels on
certain pins that I need to maintain on startup?
> >
> > Thanks for any help.
> >
> > Girish
> >
> > What is P0.31 have or connected to?
>
> regards,
> Charles
>
LPC2132/01 ISP issue
Started by ●August 20, 2009
Reply by ●August 25, 20092009-08-25
Reply by ●August 25, 20092009-08-25
Hello Girish,
Sorry I missed your original post.
It sounds to me you should focus your investigation on the oscillator. It should be running even with reset held low (someone correct me if this is wrong). With an ordinary DMM, I read about 1 volt DC on each crystal pin. My 2138 and 2148 boards read the same.
Not impossible that both your uC's are bad, but that seems unlikely. A batch of incorrect capacitors or crystals seems more probable.
Or, possibly the parameters of your crystal are such that it won't work with 33 pF caps. I presume, in this day and age, that you have unmarked surface mount caps. You could parallel them to see if the high end of the range would work. Putting them in series would be more of a challenge...
-Hugh
--- In l..., "gmpundlik" wrote:
>
> Hello,
>
> I am developing a LPC2132/01 based system. I just received the assembled PCBs and I tried to put in a test program. But the LPC2132 won't go into ISP mode.
>
> Pin P0.31 is left unconnected, and pin P0.14 is used exclusively for ISP mode select, with a pull-up of 10K. I used LPC Flash Utility v2.2.3, tried baud rates of 4800, 9600, 19200 and 38400 but none of them could detect the device id, let alone write anything to its flash.
>
> I also tried resetting the controller by shorting the reset capacitor, after power up. The controller's 3.3V supply is generated by ADP3338 LDO that does not soft start (have used it earlier with LPC2114), so I guess it is not the problem with supply voltage ramp.
>
> The voltages at all power pins are ok. The battery socket is empty (Vbat connected to VSS). However, the XTAL2 and XTAL1 clock pins are level at high and low respectively. Seems that the oscillator is not working. The crystal is 12MHz with 33pF capacitors.
>
> Errata documents do not mention anything relevant to this problem.
>
> Is there any issue or a trick to get the LPC2132 working, or could it be plain dead... on a fresh new board (two of them)!?
>
> Thanks,
>
> Girish
>
Sorry I missed your original post.
It sounds to me you should focus your investigation on the oscillator. It should be running even with reset held low (someone correct me if this is wrong). With an ordinary DMM, I read about 1 volt DC on each crystal pin. My 2138 and 2148 boards read the same.
Not impossible that both your uC's are bad, but that seems unlikely. A batch of incorrect capacitors or crystals seems more probable.
Or, possibly the parameters of your crystal are such that it won't work with 33 pF caps. I presume, in this day and age, that you have unmarked surface mount caps. You could parallel them to see if the high end of the range would work. Putting them in series would be more of a challenge...
-Hugh
--- In l..., "gmpundlik" wrote:
>
> Hello,
>
> I am developing a LPC2132/01 based system. I just received the assembled PCBs and I tried to put in a test program. But the LPC2132 won't go into ISP mode.
>
> Pin P0.31 is left unconnected, and pin P0.14 is used exclusively for ISP mode select, with a pull-up of 10K. I used LPC Flash Utility v2.2.3, tried baud rates of 4800, 9600, 19200 and 38400 but none of them could detect the device id, let alone write anything to its flash.
>
> I also tried resetting the controller by shorting the reset capacitor, after power up. The controller's 3.3V supply is generated by ADP3338 LDO that does not soft start (have used it earlier with LPC2114), so I guess it is not the problem with supply voltage ramp.
>
> The voltages at all power pins are ok. The battery socket is empty (Vbat connected to VSS). However, the XTAL2 and XTAL1 clock pins are level at high and low respectively. Seems that the oscillator is not working. The crystal is 12MHz with 33pF capacitors.
>
> Errata documents do not mention anything relevant to this problem.
>
> Is there any issue or a trick to get the LPC2132 working, or could it be plain dead... on a fresh new board (two of them)!?
>
> Thanks,
>
> Girish
>
Reply by ●August 26, 20092009-08-26
Hi Hugh,
Finally, I tracked the problem! It was a mistake in BOM that had put the crystal load capacitors into 0.1uF row! We take these things for granted, especially since BOM is automatically generated by design software. But this time it was a visible custom property that was changed to proper value, and the one used to generate BOM was not. A lesson for the lazy designer for copy/pasting component symbols...!
The schematic "looked" all ok, but the BOM it generated had wrong values. I will have to scan through the entire schematic to look for such mistakes, but it is a lot easier, now that I have got the boards to work!
I was able to get into ISP mode and write and run a test program.
Thanks all for the help.
Girish
--- In l..., "hsutherland2@..." wrote:
>
> Hello Girish,
>
> Sorry I missed your original post.
>
> It sounds to me you should focus your investigation on the oscillator. It should be running even with reset held low (someone correct me if this is wrong). With an ordinary DMM, I read about 1 volt DC on each crystal pin. My 2138 and 2148 boards read the same.
>
> Not impossible that both your uC's are bad, but that seems unlikely. A batch of incorrect capacitors or crystals seems more probable.
>
> Or, possibly the parameters of your crystal are such that it won't work with 33 pF caps. I presume, in this day and age, that you have unmarked surface mount caps. You could parallel them to see if the high end of the range would work. Putting them in series would be more of a challenge...
>
> -Hugh
>
> --- In l..., "gmpundlik" wrote:
> >
> > Hello,
> >
> > I am developing a LPC2132/01 based system. I just received the assembled PCBs and I tried to put in a test program. But the LPC2132 won't go into ISP mode.
> >
> > Pin P0.31 is left unconnected, and pin P0.14 is used exclusively for ISP mode select, with a pull-up of 10K. I used LPC Flash Utility v2.2.3, tried baud rates of 4800, 9600, 19200 and 38400 but none of them could detect the device id, let alone write anything to its flash.
> >
> > I also tried resetting the controller by shorting the reset capacitor, after power up. The controller's 3.3V supply is generated by ADP3338 LDO that does not soft start (have used it earlier with LPC2114), so I guess it is not the problem with supply voltage ramp.
> >
> > The voltages at all power pins are ok. The battery socket is empty (Vbat connected to VSS). However, the XTAL2 and XTAL1 clock pins are level at high and low respectively. Seems that the oscillator is not working. The crystal is 12MHz with 33pF capacitors.
> >
> > Errata documents do not mention anything relevant to this problem.
> >
> > Is there any issue or a trick to get the LPC2132 working, or could it be plain dead... on a fresh new board (two of them)!?
> >
> > Thanks,
> >
> > Girish
>
Finally, I tracked the problem! It was a mistake in BOM that had put the crystal load capacitors into 0.1uF row! We take these things for granted, especially since BOM is automatically generated by design software. But this time it was a visible custom property that was changed to proper value, and the one used to generate BOM was not. A lesson for the lazy designer for copy/pasting component symbols...!
The schematic "looked" all ok, but the BOM it generated had wrong values. I will have to scan through the entire schematic to look for such mistakes, but it is a lot easier, now that I have got the boards to work!
I was able to get into ISP mode and write and run a test program.
Thanks all for the help.
Girish
--- In l..., "hsutherland2@..." wrote:
>
> Hello Girish,
>
> Sorry I missed your original post.
>
> It sounds to me you should focus your investigation on the oscillator. It should be running even with reset held low (someone correct me if this is wrong). With an ordinary DMM, I read about 1 volt DC on each crystal pin. My 2138 and 2148 boards read the same.
>
> Not impossible that both your uC's are bad, but that seems unlikely. A batch of incorrect capacitors or crystals seems more probable.
>
> Or, possibly the parameters of your crystal are such that it won't work with 33 pF caps. I presume, in this day and age, that you have unmarked surface mount caps. You could parallel them to see if the high end of the range would work. Putting them in series would be more of a challenge...
>
> -Hugh
>
> --- In l..., "gmpundlik" wrote:
> >
> > Hello,
> >
> > I am developing a LPC2132/01 based system. I just received the assembled PCBs and I tried to put in a test program. But the LPC2132 won't go into ISP mode.
> >
> > Pin P0.31 is left unconnected, and pin P0.14 is used exclusively for ISP mode select, with a pull-up of 10K. I used LPC Flash Utility v2.2.3, tried baud rates of 4800, 9600, 19200 and 38400 but none of them could detect the device id, let alone write anything to its flash.
> >
> > I also tried resetting the controller by shorting the reset capacitor, after power up. The controller's 3.3V supply is generated by ADP3338 LDO that does not soft start (have used it earlier with LPC2114), so I guess it is not the problem with supply voltage ramp.
> >
> > The voltages at all power pins are ok. The battery socket is empty (Vbat connected to VSS). However, the XTAL2 and XTAL1 clock pins are level at high and low respectively. Seems that the oscillator is not working. The crystal is 12MHz with 33pF capacitors.
> >
> > Errata documents do not mention anything relevant to this problem.
> >
> > Is there any issue or a trick to get the LPC2132 working, or could it be plain dead... on a fresh new board (two of them)!?
> >
> > Thanks,
> >
> > Girish
>
