Cyclone V HPS with dual QSPI flash device


We have a dual flash connected to CS0 and CS1. When doing in sf prob in u-boot only sf probe 0:1 is working.

u-boot writes the folling values in the percs of the cfg register: (perseldec =0, which means no external 4:16 decoder)

CS0 1110
CS1 1101
CS2 1011
CS3 0111

I wonder if this is correct. When reading the HPS manual:

“if perseldec = 0, the decode is select 1 of 4
decoding on signals, qspi_n_ss_out[3:0], The asserted
decode line goes to 0.”

Shouldn’t the value not be 0…4 ?

If a value written to percslines woul appear directly on the output te additional perceldec bit wouldn’t make much sense since you can provide the input for the 4:16 decoder directly.