Agilex™ 7 Hard Processor System Technical Reference Manual

ID 683567
Date 8/13/2024
Public
Document Table of Contents

6.2. System Interconnect Clocks

The clock manager drives the system interconnect clocks. The system interconnect's clocks are part of the Interconnect clock group, which is hardware-sequenced. All clocks within a domain are synchronous with each other.

The main domain is largest synchronous domain in the interconnect, containing most of the datapath. The main domain generally consists of a single free-running clock and divided clocks with enables. Resets in the main domain depend on clock groups. Each clock group in the table below uses a single reset. Paths crossing different groups also cross asynchronous reset domains.
Table 61.  Clocks in the Main Clock Domain
Group Clock Clock Divider Reset Usage
main l3_main_free_clk - l3_rst_n clocks most of the interconnect datapath
l4_main_clk 1 DMAC and SPI
l4_mp_clk 2 EMAC, SDMMC, NAND, USB, ECC
l4_sp_clk 4 L4_SP bus
l4_sys_clk 4 L4_SYS bus
syscfg l4_sys_clk 4 syscfg_rst_n L4_SHR and L4_SEC buses
dbg cs_at_clk 1 dbg_rst_n  CoreSight
cs_pdbg_clk 2 CoreSight

The HPS-to-FPGA domain is used purely by the HPS-to-FPGA bridge. The FPGA drives the HPS-to-FPGA clock, which is asynchronous to all other clocks.

Table 62.   HPS-to-FPGA Domain
Clock Reset
h2f_axi_clock h2f_axi_reset

The Lightweight HPS-to-FPGA domain is used purely by the Lightweight HPS-to-FPGA bridge. The FPGA drives the Lightweight HPS-to-FPGA clock, which is asynchronous to all other clocks.

Table 63.  Lightweight HPS-to-FPGA Domain
Clock Reset
h2f_lw_axi_clock h2f_lw_axi_reset