I'm using 8951 to control my Bluetooth Development Kit.

Control codes of varying lengths are sent through the serial interface to instruct the kit. One example is 01H 03H 0CH 00H, which resets the kit.

It works fine, until I sent a command 01H 03H 00H 04H 0CH

After sending 00H, the rest of the bytes are not sent correctly. This was later verified by the oscilloscope. The display indicates that after 00H was sent, the RS232 Tx signal becomes LOW all the way.

I don't face any problems with sending other bytes. But when 00H is sent, the rest of the bytes are not sent correctly.

What seems to be the problem?