3 ms·
I appreciate your thorough answer, USB is pretty surprising, but just 256 byte address space, and that needs to take into account NULL (I assume?), and various
by KingLancelot 3y ago
I appreciate your thorough answer, USB is pretty surprising, but just 256 byte address space, and that needs to take into account NULL (I assume?), and various hardware devices represented in the address space, I just don’t get how it’s possible.
Honestly even 16 bit is tiny.
- jhgb 3y ago8-bit CPUs typically have a 16-bit address space though.
- j16sdiz 3y ago8bit MCU does not meant it only have 8bit address space. STM8S007xx operates on 8bit words, but have 8/16/24bit address space
- PumpkinSpice 3y agoAs others are saying, "8-bit" doesn't mean 8-bit address space. It refers to the ALU "word" size instead - i.e., how many bits you can add, subtract, multiply, or divide in a single step. (Larger types are possible, you just need to do the operations in steps, just like 64-bit math on 32-bit platforms.) Even in the 1980s, most 8-bit microcomputers had at least 64 kB memory. Today, many AVR chips will have 145 kB of memory (flash + SRAM + EEPROM), and pretty much arbitrarily more can be installed externally.
- RetroTechie 3y agoAnd many 8-bit architectures allow some registers to be used in pairs. Or have some >=16-bit registers for specific operations (eg. indirect memory addressing).