Entity: Debouncer
- File: Debouncer.vhd
Diagram
Description
Company : SLAC National Accelerator Laboratory
Description: Debouncer for pushbutton switches
This file is part of 'SLAC Firmware Standard Library'. It is subject to the license terms in the LICENSE.txt file found in the top-level directory of this distribution and at: https://confluence.slac.stanford.edu/display/ppareg/LICENSE.html. No part of 'SLAC Firmware Standard Library', including this file, may be copied, modified, propagated, or distributed except according to
the terms contained in the LICENSE.txt file.
Generics
| Generic name | Type | Value | Description |
|---|---|---|---|
| TPD_G | time | 1 ns | |
| RST_POLARITY_G | sl | '1' | '1' for active high rst, '0' for active low |
| RST_ASYNC_G | boolean | false | |
| INPUT_POLARITY_G | sl | '0' | |
| OUTPUT_POLARITY_G | sl | '1' | |
| CLK_FREQ_G | real | 156.250E+6 | units of Hz |
| DEBOUNCE_PERIOD_G | real | 1.0E-3 | units of seconds |
| SYNCHRONIZE_G | boolean | true |
Ports
| Port name | Direction | Type | Description |
|---|---|---|---|
| clk | in | sl | |
| rst | in | sl | |
| i | in | sl | |
| o | out | sl |
Signals
| Name | Type | Description |
|---|---|---|
| r | RegType | |
| rin | RegType | |
| iSynced | sl |
Constants
| Name | Type | Value | Description |
|---|---|---|---|
| CLK_PERIOD_C | real | 1.0/CLK_FREQ_G | |
| CNT_MAX_C | natural | getTimeRatio(DEBOUNCE_PERIOD_G, CLK_PERIOD_C) - 1 |
|
| POLARITY_EQ_C | boolean | ite(INPUT_POLARITY_G = OUTPUT_POLARITY_G, true, false) |
|
| SYNC_INIT_C | slv(1 downto 0) | (others => not INPUT_POLARITY_G) | |
| REG_RESET_C | RegType | (filter => 0, iSyncedDly => not INPUT_POLARITY_G, o => not OUTPUT_POLARITY_G) |
Types
| Name | Type | Description |
|---|---|---|
| RegType |
Processes
- comb: ( r, iSynced, rst )
- seq: ( clk, rst )