diff options
Diffstat (limited to 'stmhal/rtc.c')
| -rw-r--r-- | stmhal/rtc.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/stmhal/rtc.c b/stmhal/rtc.c index 91dae0d6eb..1be0b6e62b 100644 --- a/stmhal/rtc.c +++ b/stmhal/rtc.c @@ -419,17 +419,23 @@ mp_obj_t pyb_rtc_wakeup(mp_uint_t n_args, const mp_obj_t *args) { if (div <= 16) { wut = 32768 / div * ms / 1000; } else { + // use 1Hz clock wucksel = 4; wut = ms / 1000; - if (ms > 0x10000) { - wucksel = 5; - ms -= 0x10000; - if (ms > 0x10000) { + if (wut > 0x10000) { + // wut too large for 16-bit register, try to offset by 0x10000 + wucksel = 6; + wut -= 0x10000; + if (wut > 0x10000) { + // wut still too large nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "wakeup value too large")); } } } - wut -= 1; + // wut register should be 1 less than desired value, but guard against wut=0 + if (wut > 0) { + wut -= 1; + } enable = true; } if (n_args == 3) { |