Hi,
I am evaluating the FT4232H chip on the FT4232H Mini Module using libftdi.
As described in the FTDI application note AN_114 and many other sources, there
are four SPI modes defined (four combinations of the two bits cpol and cpha).
In the description of the MPSSE engine (AN2232-01 - Command Proc....) there
are only two SPI long (MSB) writes described (0x10 & 0x11 on page 7/8).
However, from my understanding there should be four modes (two for each
polarity). To make things worse, the combination which I appear to need
cpol=0, cpha=1 (=SPI mode 1) seems to be missing.
To make things appear even foolish, page 15/16 of AN2232-01 describes two SPI
modes, which from my understanding do not exist (for example 0x30: out on
positive edge, in on positive edge).
When I use a scope, no matter which write/read command I issue to the MPSSE
engine, I have not been able to get the SPI mode 1 (initial clock polarity 0,
data out on rising edge).
Any hints would be appreciated, as I am out of ideas right now...
this likely renders the chip useless for my
application.
Best
Stefan
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