Many years ago when the 8051 first came out, it had a nice CPU, a small amount of RAM and some or no ROM. It's early development consisted largely of enhancing this basic structure with more RAM and peripherals. This was followed by the development of faster versions, more peripherals and the inclusion of Flash ROM.

In recent years there seems to have been a split in its development. On the one hand we have even faster versions with more peripherals and huge amounts of memory. Not surprisingly, programming in high level languages on these devices has become practical.

However, at the other end of the spectrum there have been equally radical developments with very low pin count and very small memory devices becoming increasingly available. These devices find applications in many extremely high volume applications where every fraction of a cent of product cost counts. To save cost even more, many such devices are available as bare die for COB use. For these applications, code development in assembler is pretty much essential. If assembler can save a couple of cents by using the 0.5K ROM part instead of the 0.75K ROM part needed to include a HLL overhead then you don't use a HLL (or if you do maybe you rapidly become unemployed).

Ian