I realize that this is not a programming question, or even a Keil product issue, but I am trying to use CAN transceivers as a bus extender for TTL serial communication between processors. I am using the Motorola MC33388 (crosses with Philips TJA1054, STMicroElectronics L9669, etc). They are configured with WAKE tied to ground, EN and NSTB tied high. The problem is that I am seeing about a six microsecond delay on a dominate to recessive (0 to 1) transitions without a corresponding delay on recessive to dominate (1 to 0) transitions. At normal baud rates, using the on-board UART, this is not a problem ... but I am trying to use this interface for Flash ISP programming on a Philips P89C51RC2. The autobaud detect at the start of download screws up because the width of each one (1) bit is too short, and zero bits are too long. Has anyone had any experience with these devices? Do you know of a way to equalize the delay? BTW, the selection of resistors on the CAN lines doesn't seem to affect the problem.