PIC32MZ Oscillator - Peripheral Bus Clocks (PBCLKx)

Peripheral Bus Clocks (PBCLKx)

pbclk.PNG

PIC32MZ devices include more than one peripheral clock, allowing peripherals to run at different bus speeds, depending on the application. All peripheral clocks (except PBCLK1) also have individual enable/disable control.

Each peripheral clock is derived from the System Clock (SYSCLK) divided by the specific peripheral clock divisor setting (one to 128). The maximum clock rate for most peripheral clocks is 100 MHz. The one exception to this is PBCLK7 which is 200 MHz (drives the core).

The peripheral bus frequency can be changed on the fly by writing a new value to the divisor bits. These bits are protected from accidental writes with an unlock sequence. A state machine ensures a stable transition from one clock frequency to another.

PBCLK1 ÷ 2 can also be driven out the CLKO pin.

The following MPLAB® Harmony code provides several examples for controlling the peripheral clocks. These functions will perform all unlocking and locking and state machine control for you.

// PBCLK1=SYSCLK/2
PLIB_OSC_PBClockDivisorSet(OSC_ID_0, OSC_PERIPHERAL_BUS_1, 2);
// enable PBCLK1
PLIB_OSC_PBOutputClockEnable(OSC_ID_0, OSC_PERIPHERAL_BUS_1);
// disable PBCLK8
PLIB_OSC_PBOutputClockDisable(OSC_ID_0, OSC_PERIPHERAL_BUS_8);
© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.