RISC (Reduced Instruction Set Computer) architecture is a type of computer architecture that uses a small, highly-optimized set of instructions, rather than a more specialized set of instructions often found in other architectures such as CISC (Complex Instruction Set Computer). RISC architectures aim to simplify the instruction set, which can lead to improved performance due to simpler instruction decoding and execution.

CICS (Customer Information Control System), on the other hand, is a transaction server that runs primarily on IBM mainframe systems. It provides services for running online transaction processing (OLTP) applications, handling tasks such as data access, transaction management, and communication with other systems.

When it comes to implementing a basic MIPS (Microprocessor without Interlocked Pipeline Stages) architecture, which is a classic example of RISC architecture, you typically start with defining the basic components and instructions of the MIPS architecture. Here’s a simplified overview:

1. Registers: MIPS architecture typically has 32 general-purpose registers (labeled from $0 to $31), where $0 is hardwired to always contain the value 0. These registers are used for storing data and intermediate results during computation.
2. Instruction Set: MIPS instruction set includes basic arithmetic and logical operations, memory access instructions, control transfer instructions (branch and jump), and special instructions for system calls. Instructions are typically of fixed length (32 bits).
3. Memory: MIPS architecture uses a linear memory model where both instructions and data are stored in the same address space. Memory addresses are typically 32 bits wide.
4. ALU (Arithmetic Logic Unit): Responsible for performing arithmetic and logical operations on data stored in registers.
5. Control Unit: Decodes instructions fetched from memory and coordinates the operation of other components of the processor.
6. Pipeline: MIPS processors often employ a pipelined architecture, where multiple instructions are overlapped in execution to improve throughput.

A basic MIPS implementation would involve designing and simulating the behavior of these components, including fetching instructions from memory, decoding them, executing them in the ALU or accessing memory, and writing back results to registers.

Here’s a simple example of a MIPS instruction:

This instruction adds the contents of registers $t1 and $t2 and stores the result in register $t0.

Implementing MIPS architecture involves defining the behavior of the processor for each instruction, handling exceptions and interrupts, and ensuring proper pipelining and data forwarding to optimize performance. There are many resources and simulators available online for learning and experimenting with MIPS architecture.