The difference between address A and address A+1 is one byte. By definition.
Some hardware may raise an exception if you attempt to retrieve a value at an address that is not a (greater than 1) multiple of a byte, but that has no bearing on the definition of a byte.
I don't think the term word has any consistent meaning. Certainly x86 doesn't use the term word to mean smallest addressable unit of memory. The x86 documentation defines a word as 16 bits, but x86 is byte addressable.
ARM is similar, ARM processors define a word as 32-bits, even on 64-bit ARM processors, but they are also byte addressable.
As best as I can tell, it seems like a word is whatever the size of the arithmetic or general purpose register is at the time that the processor was introduced, and even if later a new processor is introduced with larger registers, for backwards compatibility the size of a word remains the same.
Every ISA I've ever used has used the term "word" to describe a 16- or 32-bit quantity, while having instructions to load and store individual bytes (8 bit quantities). I'm pretty sure you're straight up wrong here.
Technically the smallest addressable piece of memory is a word.
The difference between address A and address A+1 is one byte. By definition.
Some hardware may raise an exception if you attempt to retrieve a value at an address that is not a (greater than 1) multiple of a byte, but that has no bearing on the definition of a byte.
I don't think the term word has any consistent meaning. Certainly x86 doesn't use the term word to mean smallest addressable unit of memory. The x86 documentation defines a word as 16 bits, but x86 is byte addressable.
ARM is similar, ARM processors define a word as 32-bits, even on 64-bit ARM processors, but they are also byte addressable.
As best as I can tell, it seems like a word is whatever the size of the arithmetic or general purpose register is at the time that the processor was introduced, and even if later a new processor is introduced with larger registers, for backwards compatibility the size of a word remains the same.
Every ISA I've ever used has used the term "word" to describe a 16- or 32-bit quantity, while having instructions to load and store individual bytes (8 bit quantities). I'm pretty sure you're straight up wrong here.
Depends on your definition of addressable.
Lots of CISC architectures allow memory accesses in various units even if they call general-purpose-register-sized quantities "word".
Iirc the C standard specifies that all memory can be accessed via char*.
Which … if your heap always returns N bit aligned values, for some N … is there a name for that? The smallest heap addressable segment?