Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_204_416 ( id number, "chip" text, "flash size" text, "eeprom" number, "sram" number, "frequency\n[mhz]" number, "package" text )

### Question ###
what is the difference in frequency between the at90s1200 and the at90s2313 ?

### Accurate SQL ###

SELECT ABS((SELECT "frequency\n[mhz]" FROM table_204_416 WHERE "chip" = 'at90s1200') - (SELECT "frequency\n[mhz]" FROM table_204_416 WHERE "chip" = 'at90s2313'))