You copied the Doc URL to your clipboard.

10.1. Clock domains

The processor has three major clock domains:

CLK

High speed core clock used to clock all major processor interfaces. The Cortex-A8 processor uses only the rising edge of CLK.

CLK controls the following units within the processor:

  • instruction fetch unit

  • instruction decode unit

  • instruction execute unit

  • load/store unit

  • L2 cache unit, including AXI interface

  • NEON unit

  • ETM unit, not including the ATB interface

  • debug logic, not including the APB interface.

Note

The instruction fetch, instruction decode, instruction execute, load/store, and L2 cache are called the core or integer core.

PCLK

APB clock that controls the debug interface for the processor. PCLK is asynchronous to CLK and ATCLK. PCLK controls the debug interface and logic in the PCLK domain.

ATCLK

ATB clock that controls the ATB interface for the processor. ATCLK is asynchronous to CLK and PCLK. ATCLK controls the ATB interface.

Note

You can implement PCLK and ATCLK to be synchronous to CLK. You can also implement PCLK and ATCLK to run synchronously to each other.

Was this page helpful? Yes No