NetBurner Community Forum

Is the 3rd serial port of the MCF5270 on the SB70 board used?
If not, then are there pads or traces on the board where I can gain access to the port?

This is referred to as COM2 in most of the documentation. You use it just like COM1 or COM0. See the SimpleOpenSerial(), OpenSerial(), CloseSerial() calls in serial.h See also read(), write(), charavail(), dataaavail(), select() and ReplaceStdio() in iosys.h

The pins are:
J2[44] : UART2 Tx
J2[41] : UART2 Rx

Configure the pins as UART functionality (as opposed to GPIO) by using the pinconstants.h calls:
J2[44].function ( PINJ2_44_UART2_TX ) ;
J2[42].function ( PINJ2_41_UART2_RX ) ;

OpenSerial may also set this up, but better to be sure.

I don't think the handshake pins are brought out.

The pins are 3.3V locic level serial NOT RS232. I use these handy little boards all the time to do the level conversion:
http://www.acroname.com/robotics/parts/ ... -CONN.html

On the SB70 board J2 is a 10 pin unpopulated connector.

I think I found pads where I can gain access to the U2TXD and U2RXD signals between R7 and U3 right next to the processor. I really only need U2RXD, but for future reference I would like to make note of both RX and TX. From looking through the documentation for the MCF5270, it looks like the handshaking lines for UART2 are shared with the handshaking lines for UART1. That is not a problem as I do not need any handshaking lines for my current project.

3.3v is also no problem. My interface board already takes care of any level shifting required.

So my initial questions still stand, just to help validate my findings.
Is UART2 used for anything on the SB70 board?
and if not, then how can I gain access to UART2 RX and TX? I think it is the unpopulated 3 pin connector between R7 and U3.

If I could get schematics for the SB70 board, I could just figure it out myself. I have them for the MOD Modules, but not the SB70 Module.

Hi Eric_v,

Do you have new information about these pins? I see 3 pads but only two of them have connections to them. One of them have no connection on top or bottom or the board must be multilayered.

Looking better to the SB72 docs I think there are only two port 0 and 1 and they are buffered by either ttl, rs232 or rs485 levels shifters.

SB70Koll

Hi,

Yes, indeed there are 3 UART's reading the Freescale manual. I hope it can be found on the sb70 and accessed.

Regards,

SB70Koll

With the ethernet connector pointing toward the right.
The three pin connector under the processor at the very bottom of the board is

Left most U2TX
Middle U2Rx
Right Most Gnd

Paul

Paul,

Thank you very much for the information.