MICROPROCESSORS
50 questions available
Questions
In the analog signal averager design, what was the primary reason for putting the display refresh task inside the interrupt handler instead of the main loop?
View answer and explanationAccording to the global register usage list in Program 11.3, what is the function of data register D7?
View answer and explanationWhat is the memory address assigned to the `stop-flag` variable in the RAM location definitions of Program 11.3?
View answer and explanationIn the program's main loop, what is the purpose of the `BTST #START-BIT, CIO-PA-DATA` instruction followed by `BNE wait-for-zero`?
View answer and explanationWhat is the reason given for using indirect addressing through a register (e.g., `MOVE.B (A3),D0`) instead of absolute addressing (e.g., `MOVE.B ADCO,DO`) for accessing ports?
View answer and explanationIn the `get-data-int` interrupt handler routine, after an ADC value is read and added to the accumulator, what is the next step if the dwell count is not yet zero (BNE z_pulse)?
View answer and explanationWhat is the calculated execution time for the `idle` interrupt handler entry, including vectoring and return?
View answer and explanationIn the software debounce routine, after waiting for the START switch to be open, how many loops does the `check-debounce` routine execute to ensure the switch remains open before proceeding?
View answer and explanationWhat is the purpose of the `bad-int` interrupt handler routine?
View answer and explanationWhat value is loaded into CIO-CNTRL to configure the direction of Port B, and what does this configuration achieve?
View answer and explanationIn the `update` subroutine, how is the correct value from the `norm-array` selected for autoscaling?
View answer and explanationWhat is the initial value loaded into the `int5-vect` location during the `reset-entry` sequence?
View answer and explanationWhich condition leads to the longest execution time (114 microseconds) for the interrupt service routine?
View answer and explanationWhy is the `clear-arrays` subroutine considered a 'fastest looping primitive'?
View answer and explanationIn the `stop-sweep` routine, what is the purpose of the instruction `ST stop-flag`?
View answer and explanationWhat does the `decode-tbl` lookup table in the assembly program contain?
View answer and explanationWhen initializing the timer, two bytes are written to set the counting modulus of 400. What are these two bytes?
View answer and explanationWhat is the function of address register A2 in the global register usage plan?
View answer and explanationAt the very beginning of the ROM code, what two 32-bit values are defined before the first executable statement?
View answer and explanationIn the `comp-and-save` subroutine, what is the purpose of the `BCHG #7, D1` instruction?
View answer and explanationWhat is the memory address defined for the `data-array` in the program listing?
View answer and explanationIn the `wait-trig-int` routine, what happens if the external trigger signal (EXT-TRIGGER) is NOT present?
View answer and explanationWhat is the primary pathology of using a software pulse for the Z-axis if interrupts are running?
View answer and explanationHow many times per second is the complete 256-point graph displayed when the refresh is handled by the interrupt routine?
View answer and explanationIn the `auto-scale` section of the `update` subroutine, why does the code perform `TST.W D2` before the `DIVS D2, D1` instruction?
View answer and explanationWhat is the defined memory address for the LED port?
View answer and explanationWhich address register is reserved to point to the `NORM` array?
View answer and explanationWhen checking for a manual abort at the end of a sweep, the code tests the STOP-BIT. If the bit is set, to which routine does the program branch?
View answer and explanationWhat is the specified purpose of the `1's catching` input option for the STOP switch?
View answer and explanationWhat does the instruction `MOVE.B #$E0, CIO-CNTRL` accomplish in the Port A initialization sequence?
View answer and explanationWhat is the purpose of address register A3, according to the global register usage plan?
View answer and explanationIn the `idle-int` routine, what is the purpose of the instruction `ADDQ.B #1, D4`?
View answer and explanationWhat is the starting address of the `norm-array` in RAM?
View answer and explanationIn the `sweep-start-int` routine, what is the primary action taken before falling through to `get-data-int`?
View answer and explanationWhat is the execution time for the `getdata` interrupt handler entry at the end of a bin?
View answer and explanationAccording to the `main-loop` logic, after the START switch is pressed and the control panel is read, what is the next major step before entering the `update-loop`?
View answer and explanationIn the `z_pulse` routine, what instructions are used to clear the timer's interrupt request?
View answer and explanationWhat is the function of the `ASL.W #1, DO` instruction when reading the control panel?
View answer and explanationWhich port bit assignment corresponds to the `SWEEP-BIT` output?
View answer and explanationWhat is the primary function of the `re-trigger` routine at the end of a sweep?
View answer and explanationIn Program 11.3, what is the value of `DACO_OFFSET`?
View answer and explanationWhat does the instruction `EXT.L D3` accomplish in the `get-data-int` routine?
View answer and explanationHow is the `dwell_per_bin` parameter determined by the main program?
View answer and explanationWhat instruction is used to turn off the SWEEP LED at the end of a sweep?
View answer and explanationIn the `vect-init-loop`, the `DBF` instruction loops until the D0 register equals what value?
View answer and explanationWhat action does the `CLR.B stop-flag` instruction perform in the final setup before data collection?
View answer and explanationWhat is the purpose of the `NOP` instruction in the `get-data-int` handler?
View answer and explanationWhich bit of Port A is assigned to the START button input?
View answer and explanationWhat does the `BRA main-loop` instruction at the end of the `update-loop` signify?
View answer and explanationIn the Port C initialization, what value is loaded to set the port's direction, and what is the result?
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