https://www.geeksforgeeks.org/computer-organization-hardwired-vs-micro-programmed-control-unit/
1. Horizontal Micro-programmed control Unit :
The control signals are represented in the decoded binary format that is 1 bit/CS. Example: If 53 Control signals are present in the processor than 53 bits are required. More than 1 control signal can be enabled at a time.
- It supports longer control word.
- It is used in parallel processing applications.
- It allows higher degree of parallelism. If degree is n, n CS are enabled at a time.
- It requires no additional hardware(decoders). It means it is faster than Verical Microprogrammed.
- Flexible than Hard Wired
2. Vertical Micro-programmed control Unit :
The control signals re represented in the encoded binary format. For N control signals- Log2(N) bits are required.
- It supports shorter control words.
- It supports easy implementation of new conrol signals therefore it is more flexible.
- It allows low degree of parallelism i.e., degree of parallelism is either 0 or 1.
- Requires an additional hardware (decoders) to generate control signals, it implies it is slower than horizontal microprogrammed.
- Flexible than Horizontal Micro Programming