Flash memory read access in microcontrolers

Question

I use rh850 microcontroler and compiler green hills. The access to flash memory in this controler is for one assembly instruction ld.b. The write access take more instructions and time(access to specific address few times).

Are there microcontroler with not direct read access to to flash?

Answer 1

If we talk about MCUs which runs code from own flash memory, obviously that access to this memory should be as fast as possible. Therefore, read access to data in same flash "automatically" became fast and quick.

There is one characteristic in MCUs with Harvard architecture. Because RAM and flash connected to different buses, it mapped to different address spaces. This MCUs (most common example - Atmel AVR) uses separate commands to read data from flash and RAM.