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ulp: add documentation for JUMPS instruction conditions

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Hardware implements conditions LE, LT, GE, and conditions EQ and GT
are implemented in the assembler by emitting two JUMPS instructions
with other conditions.
This commit is contained in:
Ivan Grokhotkov 2018-08-07 16:57:19 +03:00
parent 72ad5a142b
commit b9f6b579f1
1 changed files with 20 additions and 1 deletions
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21
docs/api-guides/ulp_instruction_set.rst
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@ -512,10 +512,29 @@ Note that when accessing RTC memories and RTC registers, ULP coprocessor has low
- *Condition*:
- *EQ* (equal) – jump if value in stage_cnt == threshold
- *LT* (less than) – jump if value in stage_cnt < threshold
- *LE* (less or equal) - jump if value in stage_cnt <= threshold
- *GT* (greater than) – jump if value in stage_cnt > threshold
- *GE* (greater or equal) — jump if value in stage_cnt >= threshold
**Cycles**
2 cycles to execute, 2 cycles to fetch next instruction
Conditions *LE*, *LT*, *GE*: 2 cycles to execute, 2 cycles to fetch next instruction
Conditions *EQ*, *GT* are implemented in the assembler using two **JUMPS** instructions::
// JUMPS target, threshold, EQ is implemented as:
JUMPS next, threshold, LT
JUMPS target, threshold, LE
next:
// JUMPS target, threshold, GT is implemented as:
JUMPS next, threshold, LE
JUMPS target, threshold, GE
next:
Therefore the execution time will depend on the branches taken: either 2 cycles to execute + 2 cycles to fetch, or 4 cycles to execute + 4 cycles to fetch.
**Description**
The instruction makes a jump to a relative address if condition is true. Condition is the result of comparison of count register value and threshold value.