To answer my own question: After some tests I did, it seems that QSPI can be used to interface to a 32-bit bus by using 4 8-bit shift registers (with parallel outputs) and connect their serial data inputs to each their own QSPI output - this way, 32 bits can be pushed out using just 8 SPI clock puls...

1. The ESP32 has 128+kB of ROM, can't that be used for code/data, or is internal/external flash an absolute requirement to use the chip?

2. In case of internal flash, does it block the external use of the QSPI interface for other things (not necessarily memory) ?

Hi, as the title says, I would like to connect the ESP32 to a 32 bit parallel bus. I was wondering if it would be possible to use 4 8-bit serial-to-parallel shift registers and connect them using QSPI such that each 8-bit register is connected to its own QSPI data signal. This will of course only wo...