(1) The difference between revision A silicon and revision B silicon
is the addition of the
InstaSPIN™ code in
revision B silicon. The InstaSPIN code in secure ROM is execute-only with no
read access. For more details, see the
TMS320F28026F, TMS320F28027F
InstaSPIN™-FOC Software Technical Reference Manual. In
revision B silicon, the original ROM contents from revision A silicon have not
been modified. All new additions for revision B silicon have been placed in the
unused locations of ROM in revision A silicon. However, the ROM revision code
has been updated on revision B and the ROM checksum will be different between
the two revisions.