| | 1 | ## |
| | 2 | ## This file is part of the libsigrokdecode project. |
| | 3 | ## |
| | 4 | ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de> |
| | 5 | ## |
| | 6 | ## This program is free software; you can redistribute it and/or modify |
| | 7 | ## it under the terms of the GNU General Public License as published by |
| | 8 | ## the Free Software Foundation; either version 2 of the License, or |
| | 9 | ## (at your option) any later version. |
| | 10 | ## |
| | 11 | ## This program is distributed in the hope that it will be useful, |
| | 12 | ## but WITHOUT ANY WARRANTY; without even the implied warranty of |
| | 13 | ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| | 14 | ## GNU General Public License for more details. |
| | 15 | ## |
| | 16 | ## You should have received a copy of the GNU General Public License |
| | 17 | ## along with this program; if not, write to the Free Software |
| | 18 | ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| | 19 | ## |
| | 20 | |
| | 21 | ''' |
| | 22 | This protocol decoder handles the 1-Wire link layer. |
| | 23 | |
| | 24 | The 1-Wire protocol enables bidirectional communication over a single wire |
| | 25 | (and ground) between a single master and one or multiple slaves. The protocol |
| | 26 | is layered: |
| | 27 | |
| | 28 | - Link layer (reset, presence detection, reading/writing bits) |
| | 29 | - Network layer (skip/search/match device ROM addresses) |
| | 30 | - Transport layer (transport data between 1-Wire master and device) |
| | 31 | |
| | 32 | Sample rate: |
| | 33 | A sufficiently high samplerate is required to properly detect all the elements |
| | 34 | of the protocol. A lower samplerate can be used if the master does not use |
| | 35 | overdrive communication speed. The following minimal values should be used: |
| | 36 | |
| | 37 | - overdrive available: 2MHz minimum, 5MHz suggested |
| | 38 | - overdrive not available: 400kHz minimum, 1MHz suggested |
| | 39 | |
| | 40 | Channels: |
| | 41 | 1-Wire requires a single signal, but some master implementations might have a |
| | 42 | separate signal used to deliver power to the bus during temperature conversion |
| | 43 | as an example. This power signal is currently not used. |
| | 44 | |
| | 45 | - owr (1-Wire signal line) |
| | 46 | - pwr (optional, dedicated power supply pin) |
| | 47 | |
| | 48 | Options: |
| | 49 | 1-Wire is an asynchronous protocol, so the decoder must know the samplerate. |
| | 50 | The timing for sampling bits, presence, and reset is calculated by the decoder, |
| | 51 | but in case the user wishes to use different values, it is possible to |
| | 52 | configure the following timing values (number of samplerate periods): |
| | 53 | |
| | 54 | - overdrive (if active the decoder will be prepared for overdrive) |
| | 55 | - cnt_normal_bit (time for normal mode sample bit) |
| | 56 | - cnt_normal_slot (time for normal mode data slot) |
| | 57 | - cnt_normal_presence (time for normal mode sample presence) |
| | 58 | - cnt_normal_reset (time for normal mode reset) |
| | 59 | - cnt_overdrive_bit (time for overdrive mode sample bit) |
| | 60 | - cnt_overdrive_slot (time for overdrive mode data slot) |
| | 61 | - cnt_overdrive_presence (time for overdrive mode sample presence) |
| | 62 | - cnt_overdrive_reset (time for overdrive mode reset) |
| | 63 | |
| | 64 | These options should be configured only on very rare cases and the user should |
| | 65 | read the decoder source code to understand them correctly. |
| | 66 | ''' |
| | 67 | |
| | 68 | from .pd import * |
projects / libsigrokdecode.git / blame_incremental