| Copyright © 2000, 2001 ARM Limited. All rights reserved. | ARM DDI 0184B |
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| Home > Instruction Cycle Summary and Interlocks > Instruction cycle times > Multiplier cycle counts |
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The number of cycles that a multiply instruction takes to complete depends on the instruction, and on the value of the multiplier-operand. The multiplier-operand is the contents of the register specified by bits [11:8] of the ARM multiply instructions, or bits [2:0] of the Thumb multiply instructions:
For ARM MUL, MLA, SMULL, SMLAL,
and Thumb MUL, m is:
1 if bits [31:8] of the multiplier operand are all 0 or all 1
2 if bits [31:16] of the multiplier operand are all 0 or all 1
3 if bits [31:24] of the multiplier operand are all 0 or all 1
4 otherwise.
For ARM UMULL, UMLAL,
m is:
1 if bits [31:8] of the multiplier operand are all 0
2 if bits [31:16] of the multiplier operand are all 0
3 if bits [31:24] of the multiplier operand are all 0
4 otherwise.
| Copyright © 2000, 2001 ARM Limited. All rights reserved. | ARM DDI 0184B |
| Non-Confidential | |
| PDF version | |
| Home > Instruction Cycle Summary and Interlocks > Instruction cycle times > Multiplier cycle counts |