SQL & PL/SQL :: Compound Trigger Update Firing Update

After many tests I can't make work and update of the same table inside the same table.

Trying to avoid Mutating Table Error now I have
ORA-00036: maximum number of recursive SQL levels (50) exceeded

Sample Data :

create table test_compound (USERID VARCHAR2(10),APP VARCHAR2(15),LAST_UPDATED_ON TIMESTAMP);

insert into test_compound values ('user1','1',systimestamp);
insert into test_compound values ('user2','2',systimestamp-4);
insert into test_compound values ('user3','3',systimestamp-6);

CREATE OR REPLACE TRIGGER trigger_test
FOR UPDATE ON test_compound
COMPOUND TRIGGER
TYPE t_tab IS TABLE OF VARCHAR2(50);
l_tab t_tab := t_tab();
[code].......

When I execute :

update test_compound
set last_updated_on=systimestamp
where userid='user1' and app='1';

The trigger should update the first row and all the data from test_compound table where userid='user1'. Maybe the problem is that updating the same table inside the trigger is firing in a recursive way the trigger.