LPC11xx basics required

lpcware · ‎06-15-2016

Content originally posted in LPCWare by glenn@iplc.com on Wed Mar 24 09:05:09 MST 2010
Can anyone please recommend the basic interface circuits for:

the reset pin: We have had problems with the chip NOT reseting with minor power drop outs. We are using a hot supply with a slow and choppy voltage rise. Our current circuit uses a 1UF cap in series with a 200K resistor with a reverse diode to vdd. Also we have enabled the BOD set at the highest level ~2.7v for reset. And are considering a simular circuit for the LDO enable pin..

The crystal input: Not using the crystal do you just ground this XI pin?

Also, BE AWARE there are no diodes to vdd on any pin, just ESD protection (7.8v) so if you are using a resistor to hot to sense zero crossings you NEED a diode to vdd.

DO NOT use the SWCLK or SWDIO pins for any function EXCEPT programming etc..

If there is a reference for these basics I would very much like to have it.

Many Thanks in Advance to all

Glenn

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Luis Digital on Thu Sep 23 20:51:56 MST 2010
Some photos more beautiful.

LPC1111

[IMG]http://luisdigital.com/varios/lpc1111_new.jpg[/IMG]

LPC1764
[IMG]http://luisdigital.com/varios/LPC1764.JPG[/IMG]
I made a mistake, confused by the letters, as the pin 1 is bottom left (Now pin 26 in the PCB).

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Luis Digital on Mon Aug 23 17:10:09 MST 2010
Hello,

I was a little boring and I had the idea to try something new:

[IMG]http://luisdigital.com/varios/lpc1111.jpg[/IMG]

LPCXpresso compatible and works with two rechargeable batteries (1.2 V x 2).

The constant "SYSPLLCLKSEL_Val" should be changed to "0" in the file "system_LPC11xx.c".

Very flexible, small and inexpensive (you can use plastic or other material). It does not use resistors, capacitors, etc.

Among the ideas for use are: add some LEDs, transmitter / receiver infrared, Thermostat, I/O Expander, etc.

It's like having an AVR-Tiny, but with more pins, and power (unfortunately also consumes more energy).

lpcware · ‎06-15-2016

Content originally posted in LPCWare by leon_heller on Sun Mar 28 05:04:40 MST 2010

Quote: tkreyche
[FONT=Arial][SIZE=2]I don't see anyone (Leon's ref design or the 1114 xpresso board) implementing this suggestion from the manual. ??? thanks, Tom[/SIZE][/FONT]

[I][FONT=Arial][SIZE=2]Pin PIO0_1 that is used as hardware request for ISP requires special attention. Since
PIO0_1 is in high impedance mode after reset, it is important that the user provides
external hardware (a pull-up resistor or other device) to put the pin in a defined state.
Otherwise unintended entry into ISP mode may occur.[/SIZE][/FONT][/I]

I wouldn't assume that my design is correct, I haven't actually tried it yet. It looks as though the pin in question won't cause a problem, anyway.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by NXP_USA on Thu Mar 25 09:17:39 MST 2010
The state of P0.1 after reset is an input with the internal pull-up enabled, therefore no external pull-up is required.

The statement in the LPC11xx User Manual regarding the use of an external pull was incorrect and has been removed from the latest version of the document (available on the website).

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Luis Digital on Thu Mar 25 06:14:28 MST 2010

Quote: tkreyche
[FONT=Arial][SIZE=2]I don't see anyone (Leon's ref design or the 1114 xpresso board) implementing this suggestion from the manual. ??? thanks, Tom[/SIZE][/FONT]

[I][FONT=Arial][SIZE=2]Pin PIO0_1 that is used as hardware request for ISP requires special attention. Since
PIO0_1 is in high impedance mode after reset, it is important that the user provides
external hardware (a pull-up resistor or other device) to put the pin in a defined state.
Otherwise unintended entry into ISP mode may occur.[/SIZE][/FONT][/I]

You're right. But the chip does not enter ISP. Apparently the chip does not get its low logic state easily.

In tests I have conducted with other chips, and MOSFETs, the gate tends to be loaded with positive charge, while it is floating (no connection).

That might be the explanation, but NXP has the last word on this.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by ktownsend on Thu Mar 25 00:05:01 MST 2010

Quote: tkreyche
[FONT=Arial][SIZE=2]I don't see anyone (Leon's ref design or the 1114 xpresso board) implementing this suggestion from the manual. ??? thanks, Tom[/SIZE][/FONT]

[I][FONT=Arial][SIZE=2]Pin PIO0_1 that is used as hardware request for ISP requires special attention. Since[/SIZE][/FONT][/I]
[I][SIZE=2][FONT=Arial]PIO0_1 is in high impedance mode after reset, it is important that the user provides[/FONT][/SIZE][/I]
[I][SIZE=2][FONT=Arial]external hardware (a pull-up resistor or other device) to put the pin in a defined state.[/FONT][/SIZE][/I]
[I][SIZE=2][FONT=Arial]Otherwise unintended entry into ISP mode may occur.[/FONT][/SIZE][/I]

There is a pullup resistor on the ISP in this schematic ... look for the ISPEN jumper on the bottom beneath the LPC1114:

http://www.microbuilder.eu/Projects/LPC1114ReferenceDesign.aspx

lpcware · ‎06-15-2016

Content originally posted in LPCWare by tkreyche on Wed Mar 24 20:47:06 MST 2010
[FONT=Arial][SIZE=2]I don't see anyone (Leon's ref design or the 1114 xpresso board) implementing this suggestion from the manual. ??? thanks, Tom[/SIZE][/FONT]

[I][FONT=Arial][SIZE=2]Pin PIO0_1 that is used as hardware request for ISP requires special attention. Since
PIO0_1 is in high impedance mode after reset, it is important that the user provides
external hardware (a pull-up resistor or other device) to put the pin in a defined state.
Otherwise unintended entry into ISP mode may occur.[/SIZE][/FONT][/I]

lpcware · ‎06-15-2016

Content originally posted in LPCWare by Luis Digital on Wed Mar 24 09:59:15 MST 2010
Hello,

Some links to good info:
[B][SIZE=4]LPC1100 Minimal Connections- Power and Ground[/SIZE][/B]

[B][SIZE=4]LPC1100 Minimal Connections - Deep Power Down[/SIZE][/B]

[B][SIZE=4]LPC1114 Reference Design[/SIZE][/B]

[B][SIZE=4]LPC1114 Reference Design (Leon Heller ;))
[/SIZE][/B]

[B][SIZE=4]LPC1114 LPCXpresso Board (Resources)
[/SIZE][/B]

Good luck.