HP 0012C-90001 User Manual page 108

108 Section 9: 108 Section 9: Branching and Loopin Branching and Looping g g g
108 108 Section 9: Section 9: Branching and Loopin Branching and Loopin
The program line immediately following that containing the conditional test
instruction can contain any instruction; however, the most commonly used
instruction there is (. If a ( instruction follows a conditional test instruction,
program execution branches elsewhere in program memory if the condition is true
and continues with the next line in program memory if the condition is false.
Example: The following program calculates income tax at a rate of 20% on Example:
Example: Example:
incomes of $20,000 or less and 25% on incomes of more than $20,000. To
conserve program lines, the program assumes that the test value — 20,000 — has
been stored in register R
registers R and R , respectively.
1 2
Note: Note: Note: Note:
If a program requires that certain numbers be in the X- and Y-registers
when instructions such as o are executed, it is extremely helpful when
writing the program to show the quantities in each register after each
instruction is executed, as in the following diagram.
and the tax rates — 20 and 25 — have been stored in
0