Problems with DE10nano and SPI EEPROM

RocketBoards General
1

Hi everybody,

I wired an SPI EEPROM/NVRAM to the DE10nano board (using the LTC header). I implemented a bare metal application that should read the Status Register of the NVRAM (using opcode 0x05). Unfortunately the nCS goes HIGH and the CLK is disabled after the opcode was transmitted so the NVRAM will never answer to the opcode because it is disabled.
The following picture shows the signals that should be created:

NVRAM
NVRAM700×303 23.6 KB

I already checked my implementation according to the “Cyclone V Hard Processor System
Technical Reference Manual” but I did not realized a mistake in my implementation.

Does someone of you has a similar issue or a bugfix?

Kind regards
Dan

2

Afterwards you will find an plot that shows my issue (I am not allowed to add more than one embedded content):
Oszi_2
After one byte (the opcode) was transmitted the CLK is disabled and the nCS goes HIGH. The SI data is not shown in the plot.
Regards
Dan

3

Hi everybody,
I found my mistake. I have to use SPI mode 3 to get the expected signals.

Capture
Capture1193×238 38.7 KB

Regards Dan