For my graduation work I am developing a microcontroller system where the MCU (MSP430FR5739) talks to an SPI flash (SST25VF080B to be particular). I've achieved this without using the eUSCI SPI master (by bit-banging the thing) but no matter what, the flash always returns a 0x00 byte if I don't leave gigantic 2000-cycle delays between clock pulses.
On the datasheet it says that the flash could work at up to 80 MHz, and I've clocked the MSP430 at 24 MHz, so my thought process here is that it should be working without any delays at all.
My questions would be:
- The flash IC is on a daughterboard and is connected to the main board with approximately 2 inches of 22 AWG single core wire. I know that solid core wire is terrible for high frequency, but would replacing these help speed it up?
- If I most certainly have to have the delays, what else can I do to speed it up?