Wawavoun
Experienced Member
Hi All,
I have a serial interface for a home build Flex computer made with a MC68B50.
This chip need a bus timing sync clock named E and a separate rx-tx clock.
The rx-tx clock can be provided by an output of a 6522 via (CB1). In this case I use a clock at 153600 Hz and a 16 divider in the acia giving a 9600 baud transmission.
In this case everything works well.
I can also use the E (bus timing sync) signal as rx-tx clock. This signal run at 1843,2 KHz. Using the same divider this should give a 115200 baud transmission. This did not work.
I have already use this specific MC68B50 at this transmission speed (1843.2 KHz rx-tx clock and 16 divider) but with a higher E frequency (2 MHz).
I cant see where is the problem except that using the same clock for both functions is problematic but I dont find anything on this point into the datasheet.
Any opinions and may be solutions ?
Thanks and regards.
Philippe
I have a serial interface for a home build Flex computer made with a MC68B50.
This chip need a bus timing sync clock named E and a separate rx-tx clock.
The rx-tx clock can be provided by an output of a 6522 via (CB1). In this case I use a clock at 153600 Hz and a 16 divider in the acia giving a 9600 baud transmission.
In this case everything works well.
I can also use the E (bus timing sync) signal as rx-tx clock. This signal run at 1843,2 KHz. Using the same divider this should give a 115200 baud transmission. This did not work.
I have already use this specific MC68B50 at this transmission speed (1843.2 KHz rx-tx clock and 16 divider) but with a higher E frequency (2 MHz).
I cant see where is the problem except that using the same clock for both functions is problematic but I dont find anything on this point into the datasheet.
Any opinions and may be solutions ?
Thanks and regards.
Philippe