20 lines
1.5 KiB
Markdown
20 lines
1.5 KiB
Markdown
来源：PM0214 Rev 10，Page 21
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## Application program status register
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The APSR contains the current state of the condition flags from previous instruction executions. See the register summary in Table 3 on page 18 for its attributes. The bit assignment is:
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**Table 5. APSR bit definitions**
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| Bits | Description |
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|------|-------------|
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| Bit 31 | N: Negative or less than flag: 0: Operation result was positive, zero, greater than, or equal; 1: Operation result was negative or less than. |
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| Bit 30 | Z: Zero flag: 0: Operation result was not zero; 1: Operation result was zero. |
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| Bit 29 | C: Carry or borrow flag: 0: Add operation did not result in a carry bit or subtract operation resulted in a borrow bit; 1: Add operation resulted in a carry bit or subtract operation did not result in a borrow bit. |
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| Bit 28 | V: Overflow flag: 0: Operation did not result in an overflow; 1: Operation resulted in an overflow. |
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| Bit 27 | Q: DSP overflow and saturation flag: Sticky saturation flag. 0: Indicates that saturation has not occurred since reset or since the bit was last cleared to zero; 1: Indicates when an SSAT or USAT instruction results in saturation, or indicates a DSP overflow. This bit is cleared to zero by software using an MRS instruction. |
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| Bits 26:20 | Reserved. |
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| Bits 19:16 | GE[3:0]: Greater than or Equal flags. See SEL on page 105 for more information. |
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| Bits 15:0 | Reserved. |
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> 原始图片：imgs/page_21_cover.png（无图则注明无图） |