Pervasive

This device controls the clocks of the system.

= ARM Clocks = The clocks are controlled by two registers at  (ScePervasiveBaseClk). Currently, it is unknown how the values are interpreted. However,  (one word) takes values 0 to 16, and increases clock speed while   (single byte) takes values 0 to 8 and decreases clock speed. It is likely related to a PLL multiply and divide function. The input clock signal comes from a P1P40167 clock synthesizer (found on the bottom of the board under the main SoC). It takes a 27MHz crystal and generates a 37MHz clock which feeds directly into the SoC's internal PLL.

The following are tests run to determine what the values of each register corresponds to. It appears that the maximum clock speed is 500MHz and the minimum clock speed is 16MHz.

Clock Gating
Individual devices can be clock gated to preserve battery. To request the clock for a device to be enabled, do  and to request the clock to be turned off do.

Reset
Devices must be put out of reset before they are first used. To put a device out of reset, do. To put a device in reset, do.

Misc
Devices can be fully disabled? by writing a 1 to the corresponding bit of the ScePervasiveMisc (PA 0xE3100000) register. To disable the device, do.

Devices
The offsets and masks are documented below. Some devices appear to only be accessible in secure world.