diff options
Diffstat (limited to 'examples/asmled.py')
| -rw-r--r-- | examples/asmled.py | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/examples/asmled.py b/examples/asmled.py index e0d6c73ce4..917d9ba03c 100644 --- a/examples/asmled.py +++ b/examples/asmled.py @@ -1,4 +1,5 @@ # flash LED #1 using inline assembler +# this version is overly verbose and uses word stores @micropython.asm_thumb def flash_led(r0): movw(r1, (stm.GPIOA + stm.GPIO_BSRRL) & 0xffff) @@ -13,69 +14,72 @@ def flash_led(r0): label(loop1) # turn LED on - str(r2, r1, 0) + str(r2, [r1, 0]) # delay for a bit movw(r4, 5599900 & 0xffff) movt(r4, (5599900 >> 16) & 0xffff) label(delay_on) - subs(r4, r4, 1) + sub(r4, r4, 1) cmp(r4, 0) bgt(delay_on) # turn LED off - str(r3, r1, 0) + str(r3, [r1, 0]) # delay for a bit movw(r4, 5599900 & 0xffff) movt(r4, (5599900 >> 16) & 0xffff) label(delay_off) - subs(r4, r4, 1) + sub(r4, r4, 1) cmp(r4, 0) bgt(delay_off) # loop r0 times - subs(r0, r0, 1) + sub(r0, r0, 1) label(loop_entry) cmp(r0, 0) bgt(loop1) -# flash LED #1 using inline assembler -# this version uses the convenience assembler operation 'movwt' +# flash LED #2 using inline assembler +# this version uses half-word sortes, and the convenience assembler operation 'movwt' @micropython.asm_thumb def flash_led_v2(r0): - movwt(r1, stm.GPIOA + stm.GPIO_BSRRL) - movwt(r2, 1 << 13) - movwt(r3, 1 << (16 + 13)) + # get the GPIOA address in r1 + movwt(r1, stm.GPIOA) + + # get the bit mask for PA14 (the pin LED #2 is on) + movw(r2, 1 << 14) b(loop_entry) label(loop1) # turn LED on - str(r2, r1, 0) + strh(r2, [r1, stm.GPIO_BSRRL]) # delay for a bit movwt(r4, 5599900) label(delay_on) - subs(r4, r4, 1) + sub(r4, r4, 1) cmp(r4, 0) bgt(delay_on) # turn LED off - str(r3, r1, 0) + strh(r2, [r1, stm.GPIO_BSRRH]) # delay for a bit movwt(r4, 5599900) label(delay_off) - subs(r4, r4, 1) + sub(r4, r4, 1) cmp(r4, 0) bgt(delay_off) # loop r0 times - subs(r0, r0, 1) + sub(r0, r0, 1) label(loop_entry) cmp(r0, 0) bgt(loop1) +flash_led(5) flash_led_v2(5) |