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MSP430I2041: How many instruction cycles for BIS.W

pathfinder
Genius 12790 points
Part Number: MSP430I2041

Support,

Sorry if this obvious but how many cycles does "SD24CCTL0 |= SD24SC;" take?  I would think it is '1' but I'm not 100% sure when looking at the disassembly.  The whole line becomes 4 addresses - opcodes + operands.

95         SD24CCTL0 |= SD24SC; // Set bit to start conversion
820a:    D3A2 0102 BIS.W #2,&SD24_A4_SD24CCTL0

96         __bis_SR_register(LPM0_bits | GIE); // Enter LPM0 w/ interrupts
820e:    D032 0018 BIS.W #0x0018,SR

  • 0
    Guru 33653 points

    pathfinder said:

    Part Number: MSP430I2041

    Sorry if this obvious but how many cycles does "SD24CCTL0 |= SD24SC;" take?  I would think it is '1' but I'm not 100% sure when looking at the disassembly.  The whole line becomes 4 addresses - opcodes + operands.

    95         SD24CCTL0 |= SD24SC; // Set bit to start conversion
    820a:    D3A2 0102 BIS.W #2,&SD24_A4_SD24CCTL0

    No. Only instruction with registers can be executed in 1 cycle (for example mov.w R14, R15). bis.w #2,&adr will take 4 cycles. List of all  instructions with related CPU cycles you can find in family reference manual.

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