Problem getting Synchronized using Tera Term

Development Boards MicroMod
1

Hi,

I am using an LPC1768 chip, which I have soldered myself onto a custom-made PCB - and right now, I am trying to communicate with it using an FTDI FT2232 chip. I have also soldered all the necessary decoupling capacitors as well as a 12MHz crystal and also the 32.768kHz crystal. However, I keep getting the failed to autobaud - step 1 each time I used Flash Magic. Hence, I am now trying to detect where I went wrong.

I have modified the configuration settings of my Tera Term Pro. The original 9600 baud rate has been changed to 4800. Other than that I only changed the Max Com Port settings since the default is 4 and on my computer the serial port shows up as 11 (and 12 - since I used both channels A and B). After connecting, I’d press the Reset button, followed by P2.10 (ie EXT INT 0) which should make my LPC1768 go into the bootloader. Subsequently, I’ll send the “?” which I know is detected by the FT2232 chip because the LED for sending data from the PC to the chip lights up when I do so. However, I do not get any response - shouldn’t I be getting “Synchronized” back?

FYI, I have also tried with 19200 and also 9600, but so far, none worked. I don’t seem to be able to move much for my project without solving this issue. Thus I’d really appreciate any response or info from past experiences on why this occurs.

Also, when I connect a jumper to the RX and TX pins of the FT2232 for both channels (i.e. which means they are connected to pins 48-49 or 98-99 of my LPC1768), the hyperterminal/Tera Term Pro would echo whatever I type back onto the screen. In fact, the corresponding RX and TX LEDs would also be lit up.

2

My bad, I realised the EXT INT 0 pin was not properly captured due to some loose solder joints.

However, because I’m using both UART0 and UART2 for my channels A and B respectively, I seem to only get a “Synchronized” whenever I use UART0. I am aware that UART2 is powered down by default - hence is that the reason why I’m not getting “Synchronized” although I send a “?” when I use UART2 (i.e. P0.10 and P0.11) which is connected to channel B of my FT2232?

What I don’t quite understand though, is that I see a voltage drop using the oscilloscope on P0.11 on the main chip whenever I send a “?” (in fact, any characters) over. Shouldn’t the voltage remain the same since UART2 is powered down by default? Or could it be something wrong with my chip, which is why I don’t get any transmission back?

Thanks in advance!

3

You only get Synchronized on UART0 because that is the one the ISP bootloader uses.

The ISP bootloader is a program that takes a number of commands including those to download the Flash. If you want to use the other UARTs you will need to write a program to do so.