XClocks

Configure clocks for PCI, SDRAM, Core clock

XClocks

Shortest form: xc.

Read or set the CY22393 clock generator of a reference board: xclocks dump lists its registers, xclocks r <addr> / xclocks w <addr> <data> access one register, and xclocks core|sdram|pci [<MHz>] shows or sets a clock (XClocks: core clock is <f>Mhz). Setting a clock on a running board can hang it.

This is a utility for Broadcom reference boards. It talks to a named device in the SDK’s I2C device table, on the I2C bus of the switch chip itself. On a SONiC switch the platform’s fans, sensors, EEPROMs and optics are normally handled by the platform drivers on the CPU’s own I2C buses, so the device is usually missing and the command prints XClocks: cannot open I2C device clk0: ….

Unvalidated

drivshell> xclocks core

Built-in help

Usages:
           xclocks dump
               - display all registers on CY22393x.
           xclocks r <address>
               - read CY2239x register at address.
           xclocks w <address> <data>
               - write CY22393 register data at address.
           xclocks core [speed]
               - set BCM56xx core clock speed.
           xclocks sdram [speed]
               - set BCM56xx SDRAM clock speed.
           xclocks pci [speed]
               - set BCM56xx PCI clock speed.
In all cases, if a speed is not specified, the current is shown