//   This is a 'charge-pump' component for EMC2 HAL
//   Copyright 2006 Jeff Epler <jepler@unpythonic.net>
//
//   This program is free software; you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation; either version 2 of the License, or
//   (at your option) any later version.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program; if not, write to the Free Software
//   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

component charge_pump "Create a square-wave for the 'charge pump' input of some controller boards";
option singleton yes;
pin out bit out "Square wave if 'enable' is TRUE or unconnected, low if 'enable' is FALSE";
pin out bit out-2 "Square wave at half the frequency of 'out'";
pin out bit out-4 "Square wave at a quarter of the frequency of 'out'";
pin in bit enable = TRUE "If FALSE, forces all 'out' pins to be low";
function _ nofp "Toggle the output bit (if enabled)";
description """
The 'Charge Pump' should be added to the base thread function.
When enabled the output is on for one period and off for one period. To calculate the
frequency of the output 1/(period time in seconds x 2) = hz. For example if you
have a base period of 100,000ns that is 0.0001 seconds and the formula would be
1/(0.0001 x 2) = 5,000 hz or 5 Khz. Two additional outputs are provided that run
a factor of 2 and 4 slower for hardware that requires a lower frequency.""";
license "GPL";
;;
FUNCTION(_) {
    static int acc;
    if ( enable ) {
        acc++;
        out = (acc & 0x1);
        out_2 = (acc & 0x2);
        out_4 = (acc & 0x4);
    } else {
	out = 0;
	out_2 = 0;
	out_4 = 0;
    }
}