read data file?

i have to update the values of this signal reading them from an external text file which includes also the location of the signal which has to be updated (e.g0,3), (2,4) etc.) and the time at which the signal has to be updated( 400 ns, 600ns-more than one signal of the array may be updated at the same time).
Does anybody know how to make it or have any examples?
Thx

type fault_matrix_type is array(0 to 7, 0 to 7) of std_logic_vector(15 downto 0);
fault_inj : out fault_matrix_type;

icsmen