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# 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)
movt(r1, ((stm.GPIOA + stm.GPIO_BSRRL) >> 16) & 0x7fff)
movw(r2, 1 << 13)
movt(r2, 0)
movw(r3, 0)
movt(r3, 1 << 13)
b(loop_entry)
label(loop1)
# turn LED on
str(r2, [r1, 0])
# delay for a bit
movw(r4, 5599900 & 0xffff)
movt(r4, (5599900 >> 16) & 0xffff)
label(delay_on)
sub(r4, r4, 1)
cmp(r4, 0)
bgt(delay_on)
# turn LED off
str(r3, [r1, 0])
# delay for a bit
movw(r4, 5599900 & 0xffff)
movt(r4, (5599900 >> 16) & 0xffff)
label(delay_off)
sub(r4, r4, 1)
cmp(r4, 0)
bgt(delay_off)
# loop r0 times
sub(r0, r0, 1)
label(loop_entry)
cmp(r0, 0)
bgt(loop1)
# 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):
# 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
strh(r2, [r1, stm.GPIO_BSRRL])
# delay for a bit
movwt(r4, 5599900)
label(delay_on)
sub(r4, r4, 1)
cmp(r4, 0)
bgt(delay_on)
# turn LED off
strh(r2, [r1, stm.GPIO_BSRRH])
# delay for a bit
movwt(r4, 5599900)
label(delay_off)
sub(r4, r4, 1)
cmp(r4, 0)
bgt(delay_off)
# loop r0 times
sub(r0, r0, 1)
label(loop_entry)
cmp(r0, 0)
bgt(loop1)
flash_led(5)
flash_led_v2(5)
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