AR# 873

ABEL - How can I assign global buffers in ABEL code?

描述

Keywords: abl, BUFG, BUFGP, instantiate

How can I assign global buffers in ABEL code?

解决方案

In your FPGA design, use the EXTERNAL statement to instantiate global buffers, as shown in the following example:

Example:

MODULE instbuf
TITLE 'instantiating a bufgp'
d pin;
q pin istype 'reg';
c pin;
clki node;
temp node;
bufgp external (I -> O);
mybuf functional_block bufgp;

EQUATIONS
q := d;
temp = c;
mybuf.I = temp;
clki = mybuf.O;
q.clk = clki;
END



You can also assign global clocks in your CPLD designs with the BUFG property:

ABEL syntax:
xilinx property 'bufg=clk signal_name';

UCF syntax:
inst <ibuf_name> bufg=clk;
AR# 873
日期 07/28/2009
状态 Archive
Type 综合文章