Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.1.7.1.2. Clock Manager Configurable Registers

You must configure various registers within the clock manager for the EMAC controller to perform properly. The following table provides a summary of the important clock manager register bits that control operation of the EMAC.
Table 169.  Clock Manager Settings
Register.Field Description
en.emacptpen emac_ptp_clk output enable.

en.emac0en

en.emac1en

en.emac2en

Enables clock emac0_clk, emac1_clk and emac2_clk output.
Note: There are corresponding ens and enr registers that allow the same fields to be set or cleared on a bit-by-bit basis.
bypass.emacptp
EMAC PTP clock bypass. This bit indicates if the emac_ptp_clk is bypassed to the input clock reference of the peripheral PLL.
  • 0x0 = No bypass occurs.
  • 0x1 = emac_ptp_clk is bypassed to the input clock reference of the main PLL.
Note: There are corresponding bypasss and bypassr registers that allow the same bits to be set or cleared on a bit-by-bit basis.

bypass.emaca

bypass.emacb

Clock bypass. This bit indicates whether emaca_free_clk or emacb_free_clk is bypassed to the input clock reference of the main PLL.
  • 0x0 = No bypass occurs.
  • 0x1 = emac*_free_clk is bypassed to the input clock reference of the main PLL.
Note: There are corresponding bypasss and bypassr registers that allow the same bits to be set or cleared on a bit-by-bit basis.

emacctl.emac0sel

emacctl.emac1sel

emacctl.emac2sel

EMAC clock source select. This bit selects the source for the emac* clk as either emaca_free_clk or emacb_free clk
  • 0x0 = emaca_free_clk
  • 0x1 = emacb_free_clk