Lab 1 Tasks

Requested Functions

• uint8_t bit_clear(uint8_t value, uint8_t bit)
• uint8_t bit_set(uint8_t value, uint8_t bit)
• int bit_is_set(uint8_t value, uint8_t bit)
• uint8_t bit_lsb(uint16_t value)
• uint8_t bit_msb(uint16_t value)
• uint8_t bit_mask(unsigned first_bit, ...)
• int rtc_read_date(lcom_rtc_date_t *date)
• int rtc_read_time(lcom_rtc_time_t *time)

Guided Gaps

• Build masks from bit positions.
• Decide how to handle out-of-range bit numbers.
• Use a sentinel to stop the variadic bit_mask list.
• Poll RTC_REG_A until RTC_UIP is clear.
• Keep BCD conversion small and inspectable.
• Check output pointers before writing.

IMPORTANT

Do not change RTC configuration. Interpret the mode reported by the device instead of forcing the device into the mode you prefer.

Common Mistakes

• Treating BCD as binary.
• Forgetting that bit positions start at zero.
• Returning a mask value when the API asks for boolean-like output.
• Writing a partial date/time structure after one read failed.

Next: checks and references.