Hi,
I seem to be having an issue getting the TMS3705 into Synchronous mode. I have it working fine in Asynchronous mode.
The process I use is as follows:
1. TXCT low for 50us
2. 3ms later send TXCT low
3. Send MCW - TXCT 128us low + 640us high + 256us low
4. Keep TXCT low for approx 75ms, except for when the Diagnosis bit is clocked out.
5. TXCT set high and wait for SCIO to go high.
6. Attempt to clock out SCIO.
I "seem" to get the first byte out, but don't get subsequent bytes. I'm not sure what I an doing wrong.
Below are some scope images of the process. TXCT is green, SCIO yellow. Ignore the TXCT voltage it was set to 10x.
This is the full "transaction"
This is the start (50us wake up followed by MCW)
MCW and clocking out diagnosis byte
Zoom in on the diagnosis byte
Clocking out the data bytes. Note only 1 byte gets returned.
