Modify your program so that it performs the following: 1. set up port F so that RF00 and RF01 are outputs and all the other pins on port F are inputs. 2. enable the weak pull up resistor for RE00. 3. turn on LD4 and turn o LD5. 4. wait until the button is pressed. 5. wait until the button is relased. 6. call the delay subroutine. Note this changes $t9. 7. toggle the state of LD4. (In other words, if LD4 is on, then turn it o ; if LD4 is o , then turn it on.) 8. go back to step 4.

Note: you might need some of the information in Appendix A, extracted from the PIC32 Family Reference Manual (TRISx, PORTx & LATx). Also, you might need to recall that you can use the la pseudo-instruction to load the address from a label into a register, and the li pseudo-instruction to load a constant into a register. For example: la $t0, TRISA li $t1, 0x1234FFFF