time_of_day Clock with Record

Group the time value in a record, then place the shared type, constants and functions in a package.

Behaviour

• time_of_day_pkg.vhd declares t_time_of_day with hours, minutes, seconds;
• f_is_valid accepts only 00:00:00 to 23:59:59;
• f_next_second increments by one second and wraps after 23:59:59;
• i_reset='1' forces 00:00:00;
• i_load='1' loads i_time only if the time is valid;
• i_enable='1' increments by one second;
• priority: reset, then load, then enable.