One issue is that on higher data rate the CPU is resetting it self more the 115200 .. 10000000 it is not depending only on speed but also in amount of bytes sent.
In the MPC860 manual it written that SMC (core 25MHz) support 220Kbs we here want to have it 1MHz CPU speed of 66MHz.
As I understood from the Manual appendix B. for Serial performance is that the performance is depending on some factors such as SMC internal FIFO (2 bytes) and if the CPM is busy with other jobs.
1. Question is if we intend to use the SMC is that realistic to expect continuos communication of 1 Mb FD (one mega bit) at all.
2. Is that crashing of the CPU could happen because of CPM overloading ?
3. Is there any microcode patch that can fix this.