Commit 71dcd519 authored by Damien George's avatar Damien George
Browse files

examples: Add example script to flash an LED using inline assembler.

parent 6ce42775
# flash LED #1 using inline assembler
@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)
subs(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)
subs(r4, r4, 1)
cmp(r4, 0)
bgt(delay_off)
# loop r0 times
subs(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'
@micropython.asm_thumb
def flash_led_v2(r0):
movwt(r1, stm.GPIOA + stm.GPIO_BSRRL)
movwt(r2, 1 << 13)
movwt(r3, 1 << (16 + 13))
b(loop_entry)
label(loop1)
# turn LED on
str(r2, r1, 0)
# delay for a bit
movwt(r4, 5599900)
label(delay_on)
subs(r4, r4, 1)
cmp(r4, 0)
bgt(delay_on)
# turn LED off
str(r3, r1, 0)
# delay for a bit
movwt(r4, 5599900)
label(delay_off)
subs(r4, r4, 1)
cmp(r4, 0)
bgt(delay_off)
# loop r0 times
subs(r0, r0, 1)
label(loop_entry)
cmp(r0, 0)
bgt(loop1)
flash_led_v2(5)
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment