Internal interruption learning

Today I learnt internal interruption.I useAssembly Language by WangShuang. The chapter is 12. 

Interruotion information is a type of special information with which CPU will stop executing the next instruction (cs:ip) to deal.There are internal interruption and external interruption. 

Internal interruptions happen in 4 situations:

1. division error. (0)

e.g. overflow happens when 'div' instruction is executed.

2. single step executed. (1)

3. 'into' instruction (4)

4. 'int' instruction (n)

Interruption-type-code:

1 byte