Other Parts Discussed in Thread: DRV8316
We have replaced the MCT8316ZT chip on a MCT8316ZTEVM with a MC8316ZR chip.
Reading all registers via SPI works fine, but I cannot get the chip to accept any writes.
I have tried slower bit rates, other values and other variations with same results. I can set various error bits in status bytes by running a motor from the chip, but values in control bytes never change.
Do I have to do something more than setting the REG_LOCK bits to 011b (3h) to make the chip accepts writes?
See signal plot below for sequence of reading first three status registers and then attempts to write followed by read on each control register:
Detail of one word write for timing: