Clock Frequency - Xilinx Kintex UltraScale KCU1500 User Manual

Sdaccel platform acceleration development board

Table of Contents

More information on map_connect can be found in the SDAccel Environment User Guide

(UG1023)

[Ref 4]

Clock Frequency

By default, the kernel clock of the platform runs at 300 MHz, and the optional kernel clock

2 runs at 500 MHz. Unless kernel clock 2 is explicitly used by an RTL kernel, all kernel data

path logic is synchronous to kernel clock. See platform clocking for details.

To override the default kernel clock frequency with a different frequency specification, the

XOCC script would contain the following switch format:

--kernel_frequency <freq_in_mhz>

For example, to specify that the kernel clock frequency should target 200 MHz rather than

the default of 300 MHz:

--kernel_frequency 200

If kernel clock 2 is used by the RTL kernel, then the switch takes a key-value format, where

kernel clock is identified by key 0 and kernel clock 2 is identified by key 1.

For example, to specify that the kernel clock frequency should target 250 MHz rather than

the default of 300 MHz, and that kernel clock 2 should target 400 MHz rather than the

default of 500 MHz, as follows:

--kernel_frequency 0:250|1:400

To instruct the SDAccel System Compiler to use the optional kernel clock 2, a user's RTL

kernel must implement the following input port naming convention. The user is responsible

for ensuring proper clock domain crossing from the kernel clock to kernel clock 2 in the

ingress direction (slave interface), and from kernel clock 2 to kernel clock in the egress

direction (master interface(s)).

ap_clk, which the SDAccel System Compiler will drive with the kernel clock

ap_rst_n, which the SDAccel System Compiler will drive with the active-low reset

synchronous to kernel clock

ap_clk_2, which the SDAccel System Compiler will drive with the kernel clock 2

ap_rst_n_2, which the SDAccel System Compiler will drive with the active-low

reset synchronous to kernel clock 2

See the SDAccel Environment User Guide (UG1023)

Optimization Guide (UG1027)