“Assembly Language”, 3rd Edition by Wang Shuang Chapter 10: CALL and RET Instructions Experiment 10: Writing Subroutines (Page 206) ———————————— Note: Since Experiment 10 has three questions, and each question is more complex than previous experiments with longer code, it is divided into three articles. This is the reference answer for Question 2. ———————————– 2. … Read more
Overview of Ret and Retf Instructions In 8086 assembly language, <span>call</span> and <span>ret</span> instructions are crucial for implementing subroutine (procedure) calls. They achieve control flow transfer by modifying the IP or simultaneously modifying both CS and IP, utilizing the stack to save and restore the return address. Principle of the Ret Instruction <span>ret</span> instruction is … Read more
“Assembly Language”, 3rd Edition by Wang Shuang Chapter 10: CALL and RET Instructions Experiment 10: Writing Subroutines (Page 206) ———————————— Note: Since Experiment 10 has three questions, and each question is more complex than previous experiments with longer code, it is divided into three articles. This is the reference answer for Question 1. ——————————- In … Read more
“Assembly Language”, 3rd Edition by Wang Shuang Chapter 10 CALL and RET Instructions Experiment 10 Writing Subroutines (Page 206) ———————————— Note: Since Experiment 10 has 3 questions, and each question is more complex than previous experiments with longer code, it is divided into three articles. This is the reference answer for Question 3. ———————————– 3. … Read more
In microcontroller programming, writing subroutines is very important as it not only enhances code reusability but also makes the main program structure clearer and easier to maintain. However, writing efficient subroutines is not an easy task and requires consideration of multiple aspects. So let’s take a look at what areas need attention. 1. Subroutine Naming … Read more
ret and retf Instructions <span>call</span> and <span>ret</span> are transfer instructions that control the program flow by modifying the IP (Instruction Pointer) or simultaneously modifying both the CS (Code Segment Register) and IP. These instructions are typically used together to implement the design of subroutines (functions). ret Instruction <span>ret</span> (return) instruction pops data from the stack … Read more
1. Problem Analysis We need to write a subroutine that displays a given byte of data in hexadecimal format at the center of the screen. One byte should be represented by two hexadecimal characters, corresponding to the high 4 bits and low 4 bits of the value. Key Points: Separate the high 4 bits and … Read more