DSP
Used for signal processing as part of the CD/DVD drive. Not to be confused with MechaCon in this matter, which is responsible for the drive mechanics among many other functions.
DSP firmware resides in a mask-ROM inside the DSP. Several firmware versions might exist for the same DSP hardware revision.
At least one version of the DSP's firmware (specifically the CXD3098Q) has a tendency to crash MechaCon by sheer bad luck or on badly readable discs (e.g. badly burned/low-quality DVD-R discs or scratched original discs), overvolting the focus/tracking coils of the laser and killing them and also the driver IC in the process. Several hardware-based mitigations/"fixes" have been developed by the community to address this issue with varying degrees of success. The most well known of these fixes have been the "Romeo-mod"/"LA-fix" for SCPH-500xx/5500x consoles and "summ0ne's fix" for some SCPH-700xx consoles; however, the only reliable fix is the Matrix team's PIC-fix which monitors communication between DSP and MechaCon and turns off the console when a crash occurs, just like the hotfix made by Sony itself.
The CXD3098Q DSP chips of DEX models (DTL-H5xxxx & DTL-H70xxx) are not capable of producing the crash. This was fixed by Sony on the software. A dump of the DSP firmware on these units revealed that the only difference between retail and DEX firmware is a -1 (signed byte) at the end of the firmware
Revisions
- CXD1869Q (GH-001, GH-003)
- CXD1869AQ (GH-004, GH-005, GH-006, GH-007, GH-008, GH-010, GH-012, GH-013, GH-014)
- CXD1869BQ (GH-010, GH-012, GH-013, GH-014)
- CXD1886Q (GH-013, GH-014, GH-015, GH-016)
- CXD3098Q (GH-017, GH-018, GH-019, GH-022, GH-023, GH-026, GH-027, GH-029, GH-032, GH-035, GH-036, GH-037, GH-040, GH-041, GH-051, GH-052, GH-061, XPD-001, XPD-005)
- Has a (very likely) intentional bug in the firmware which causes MechaCon to crash/freeze when bad ECC sectors are read (e.g. on badly burned, low quality or scratched discs). This likelyhood is increased on ARM-based Dragon MechaCon, thus SCPH-500xx/5500x units up to some SCPH-700xx units. Some later subrevisions of the GH-032/GH-035 boards implement some safety circuit hotfix to prevent this from happening, they can be identified via the Mechacon version, if it is 6.04 or newer the console has the factory safety circuit.
- CXD3098AQ (GH-052, GH-061, GH-062, GH-070, GH-071, GH-072)