Blog

Match the instruction to its addressing mode

Given the ripple carry adder shown below: What is the value of C2? [C2] If the A & B operands are considered to be 2’comp numbers did the operation overflow? [ov2s] If the A & B operands are considered to be unsigned numbers did the operation overflow [ovun]

; Routine takes max of two arguments (R0,R1) returns in R0 ; R0 = Argument 1 ; R1 = Argument 2 ;  Computes the max of R0 and R1 and places it in R0 MAX  [1]                          ; negate R1               [2]               [3]                                      ; compare R0 to R1              [4]                                     ; decide based on comparison              [5] DONE  RET This routine is [6]

A memory has 6 address bits and a data word size of 4-bits: The total capacity is [1] The number of words is [2] An appropriate name for its data output would be [3]

Form an LC-3 instruction to move the contents of R4 to R2  (i.e. R2 ← R4) [op] [s1], [s2]  

What statement can be made about these adders  

Context restore of R0 at end of the STREND routine This code [1] the [2] will be [3] this will result in [4]

Simulate the following code in your head.  Then answer the questions posed. This code performs [Alg] When finished R1 will contain [R1] The last 9-bits of the “BR LOOP” instruction are: [offset] Are there any clues that this code was intended to work with the lc3os? [lc3os]    

Based on behavior the select lines (S[1:0]) were set to? Answer as a 2-bit binary number.

Address: Contents: Code: 0x0200 [1] 0x0201 [2] 0x0202 [3] 0x0203 [4] 0x0204 [5] 0x0205 [6] 0x0206 [7] 0x0207 [8] For the code shown fill in the values in memory at the specified addresses.  If a value is unknown enter ????