Some code I threw together because I needed to transfer some files from my PC to a flash chip via some UART lines.
I used an ATTiny1614 as the MCU and a MX25L1606E as the external memory chip. I used the Serial library's default 64bytes as the size of the chunks to send from my pc to the chip. Once the buffer on the MCU reaches 256 bytes I then write the entire buffer to the memory chip via its page program functionality.
This code is not overly optimized..just something I put together because I needed to and I thought it should be on my profile.