Module rtc 

Available on gb_pak_rtc and crate feature pak only.

The MBC3 clock: seconds to days, running on the cartridge battery.

The clock keeps time while the console is off, so a game can tell how long the player was away.

Latching

The counters inside the controller are not readable. What the window shows is a snapshot of them, and latch takes a fresh one. Reading straight through without one would mix an old second with a new minute, since the five registers arrive one at a time and the clock does not wait.

let (h, m) = gb_pak::rtc::latch(|c| (c.hours(), c.minutes()));

Trusting the time

A cartridge whose clock has never been set may hold noise.

Structs

Latch

One snapshot of the clock.

Time

What the clock counts: time since it was set, not a calendar date.

Functions

clear_overflow

Acknowledge a day-counter wrap.

latch

Snapshot the clock, switch the RAM on, and read it inside f.

set

Set the clock. Starts it if it was stopped, and clears Latch::overflowed.

set_halted

Stop the clock, or start it again.

time

Snapshot the clock and read all of it.