Connecting to LPC2368

[steved]

Having a rough time here.

I designed a new board with a LPC2368 on it.

Signals for the INTO and RST are put in as described in the schematics of the Keil development board. I am getting a toggle on the RST and INTO when attempting to program. Rx, Tx, Gnd, eventaually go to COM0 through RS232 IC.

Tx is transmitting something.

Rx never moves. The system is not being held down.

INTO and RST toggle.

12Mhz crystal, not sure when this should start ossilations since it is controlled by the uC. Perhaps this is the source of my problems?

Any pointers or suggestions would be appreciated. I have no more ideas.

Thanks!

[steved]

Further to this.

Can I program via COM0 with a totally new chip?

When I look at PIN3 of the DB9, and am in terminal mode, data is being transmitted.

I am all out of suggestions.

Thanks for your time

[steved]

More unknowns:

The Keil schematic shows that P2.10 is connected to DB9 pin 7(RTS), and the reset is connected to pin 4(DTR) of the DB9 connected

Whereas

The flash magic documentation indicates that reset should be connected to pin 4(DTR) and pin 7(RTS) should be connected to 0.14 on the uC.

I am going with the first option since it seems to program on the development board.

[steved]

Just posting when I have questions....

Do you need a bootloader program in the IC before you are able to ISP?

In otherwords, can you program a totally new blank chip or do you HAVE to use a JTAG first to get in startup code so that the ISP will work?

[steved]

Final test before almost throwing everything out the window....

Populated another PCB with only bare minumum. RS232 chip, uC, control circuitry. Still unable to connect. Always failing Step 1, Autobaud.

Suggestions appreciated, I am all out of gas.

[steved]

Attached find a scope ready of rst (top) and P2.10 bottom. The glitch in the middle is something that the application FM is putting on the line, I wonder if this signal is correct? Does not seem like it.

[Andy Ayre]

The glitch is probably due to the COM port being opened and closed when it is configured. Can't avoid that - blame Microsoft. However coming out of reset the ISP entry signal is low, which is the important part.

The ISP entry pin is not the same on all devices in the LPC2xxx family. The circuit in the Flash Magic documentation is just an example for one of the devices, so yes, very likely that you need to use a different pin.

Have you put your scope on the RxD pin to see if the '?' is arriving at the device? Flash Magic will transmit this when you attempt to perform an ISP operation. If yes, do you see data coming out of the TxD pin? If no, do you see the '?' on the PC side of the RS232 transciever?

Devices come with a bootloader. See the memory map in the device user manual from NXP.

Andy

[steved]

Thanks for your response.

I have scoped out the pin right at the device and a signal is getting there, not sure if it is a ? but I can check. I am assuming that it is since it is being sent from FM.

Pin 2.10 is the correct pin to be strobing, that has been confirmed on a couple of other docs.

After the ? is seen on the pins of RxD on the device, there is no data on the TxD. This confirms that at least 1/2 of the RS232 driver is working. I will lift a pin on the 232 device to see if it is holding the signal down and that is why I am not seeing the Tx information coming out.