23 lines
1.5 KiB
Markdown
23 lines
1.5 KiB
Markdown
|
来源：STM32 Cortex®-M4 MCUs and MPUs Programming Manual Rev 10，Page 21
|
|||
|
|
|
|||
|
|
Application program status register
|
|||
|
|
|
|||
|
|
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:
|
|||
|
|
|
|||
|
|
**Table 5. APSR bit definitions**
|
|||
|
|
|
|||
|
|
| Bits | Description |
|
|||
|
|
|------|-------------|
|
|||
|
|
| Bit 31 | N: Negative or less than flag:<br>0: Operation result was positive, zero, greater than, or equal<br>1: Operation result was negative or less than. |
|
|||
|
|
| Bit 30 | Z: Zero flag:<br>0: Operation result was not zero<br>1: Operation result was zero. |
|
|||
|
|
| Bit 29 | C: Carry or borrow flag:<br>0: Add operation did not result in a carry bit or subtract operation resulted in a borrow bit<br>1: Add operation resulted in a carry bit or subtract operation did not result in a borrow bit. |
|
|||
|
|
| Bit 28 | V: Overflow flag:<br>0: Operation did not result in an overflow<br>1: Operation resulted in an overflow. |
|
|||
|
|
| Bit 27 | Q: DSP overflow and saturation flag: Sticky saturation flag.<br>0: Indicates that saturation has not occurred since reset or since the bit was last cleared to zero<br>1: Indicates when an SSAT or USAT instruction results in saturation, or indicates a DSP overflow.<br>This bit is cleared to zero by software using an MRS instruction. |
|
|||
|
|
| Bits 26:20 | Reserved. |
|
|||
|
|
| Bits 19:16 | GE[3:0]: Greater than or Equal flags. See SEL on page 105 for more information. |
|
|||
|
|
| Bits 15:0 | Reserved. |
|
|||
|
|
|
|||
|
|
> 原始图片：imgs/page_21_*.png（无图则注明无图）
|