There are multiple security levels implemented in
the device and HIC module to prevent unauthorized access:
- Level 1: The device must turn on the clock for HIC and enable the HIC
using HICGCR.HICEN before any access to the device region can be made. The
configuration registers are read-only by the host.
- Level 2: MEM_CFG_REGS.GSxACCPROT0.HICWRPROT_GSy enables and disables
write access to the GSRAM by the HIC.
- Level 3: HICMODECR.EN_HOSTWREALLOW, HICMODECR.EN_DEVACC, and
HICHOSTCR.EALLOW_EN further restricts access by enabling/disabling EALLOW
and device region access by host.
- Level 4: HICLOCK register can be used to lock the configuration
registers from further writes. This register is read-only by the host.
- Level 5: The state of the
lock register can be commited with the HICCOMMIT register which will prevent
further changes until device is reset.