2.3 - Lab 2: Introduction to Assembly Language 1.1 2006/05/18 16:42:23.794 GMT-5 2006/05/18 16:44:00.129 GMT-5 Naren Anand nanand@rice.edu Naren Anand nanand@rice.edu assembly ez430 msp430 A lab that introduces a student to assembly language programming. In this lab you will be asked to write simple assembly statements, follow already written assembly statements, and finally to reproduce the SOS light blinking program from Lab 1 in assembly. Formulate instructions to do the following things: Set bit 3 to 1 at the memory address 0xd640 while leave bits 0-2 and 4-16 unaffected. Jump to the instruction labeled POINT if the carry bit is set. Shift register R6 right one place while preserving the sign. Examine this loop: ... more instructions... Mov.w &I, R4 Cmp.w #0x0000, R4 JZ After_loop Start_loop: Dec.w #0x0001, R4 JZ After_loop BR #Start_loop After_loop: ...more instructions... How many times will this loop execute? Why do we use the BR instruction with a #Start_loop, but with the JZ we use a plain After_loop? What does the first JZ instruction do? If we did not have this initial Cmp and JZ, what (possibly) inadvertent effect might occur? Re-write the blinking light program from Lab 1 using assembly code instead. As you may recall, the program must blink "SOS" (which is "... --- ...") and conform to the following Morse Code standards: The ammount of time of a dash is equivalent in length to 3 dots. The ammount of time between parts of a letter is equivalent in length to one dot. The ammount of time between letters is equivalent in length to 3 dots. The ammount of time between words (assume each SOS is a word) is equivalent to 5 dots.