Write back buffer in lpc
The write-back mechanism is a method usually used to guarantee the consistency of the data in memories in a multi-agent system (multi-core systems but also with DMAC - controller of hard disks - for instance). In this case is meant to avoid writing data in the RAM in case it's required in short time from the CPU.

It means that the data is not immediately written to the memory, but held in a register until anyone requests it. It's the alternative to the write-through policy, in which every time a write-to-RAM instruction is called for data, it's written directly to the RAM.

It prevents CPU stalls (that are clock cycles in which the CPU is waiting) because the result of the instruction is saved in the register for future access, and it's written to the memory only if needed (another "write" instruction requesting the buffer, that has to be emptied); so you don't need to save into (and load from) RAM a value that is requested in the next instruction.

In this way the content of the RAM is not always up-to-date, so it shows a trick to guarantee that a certain data is written before a reset.