SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
ROMs are read only memory; unlike RAMs, data or parity bits cannot be modified to introduce errors for diagnostic coverage of parity checking logic. The following method is used to check health of parity checking logic in ROMs.
The probability of both circuits having fault is unlikely ; therefore, parity errors will be certainly detected.
To generate the error, a test bit FORCE_ERROR is added. When the FORCE_ERROR bit is set, the parity bit going to one of party checker is inverted, thereby introducing an uncorrectable error. An uncorrectable error is generated only if there is an error on all parity checker, that is, address, data [15:0] and data [31:16]. This will ensure that all three parity checkers are working as expected.