source: multiio/pcmmio/original/README @ 9175425

Last change on this file since 9175425 was 9175425, checked in by Joel Sherrill <joel.sherrill@…>, on Jul 22, 2009 at 4:50:06 PM

2009-07-22 Joel Sherrill <joel.sherrill@…>

  • README, main_pcmmio_adc.c, main_pcmmio_dac.c, main_pcmmio_din.c, main_pcmmio_dout.c, pcmmio_commands.h: Switch to rtems/string2.h methods. Verify negative voltages are allowed as input.
  • Property mode set to 100644
File size: 1.5 KB
Line 
1#
2#  $Id$
3#
4
5This is a port of the Winsystems Linux driver to RTEMS.
6
7In general, the goal was to minimize changes to the user level
8library and only replace Linux IO calls to the device driver
9with direct access functions.
10
11The driver uses 4 Classic API Barriers.
12
13--joel sherrill
14
15Issues
16======
17+ The library is not reentrant. The GNU/Linux version uses global variables
18  to track the state of certain variables and access to these is not protected.
19  This design flaw is carried over into the RTEMS version.
20
21+ We want to timestamp samples and the initial code did not do that.  I
22  added this.
23
24RTEMS Shell Commands
25====================
26The following RTEMS Shell configuration aids are defined to assist in
27adding PCMMIO related commands to your shell.
28  CONFIGURE_PCMMIO_ALIASES
29  CONFIGURE_PCMMIO_COMMANDS
30
31pcmmio_din - Read Discrete Inputs
32    pcmmio_din [-i iterations] [-p period] [-v]
33    Where: maximum iterations defaults to 1
34           the period is in milliseconds and defaults to 1000
35
36pcmmio_dout - Write a Discrete Output
37    pcmmio_dout bit value
38    Where: bit must be 0-47
39           value must be 0 or 1
40
41pcmmio_adc - Read Analog Inputs
42    pcmmio_adc [-i iterations] [-p period] [-v]
43    Where: maximum iterations defaults to 1
44           the period is in milliseconds and defaults to 1000
45
46pcmmio_adc - Write Analog Output
47    pcmmio_dac dac voltage
48    Where: dac must be 0-7
49           voltage must be -10V to +10V
50
51Aliases
52  + adc  - alias for pcmmio_adc
53  + dac  - alias for pcmmio_dac
54  + din  - alias for pcmmio_din
55  + dout - alias for pcmmio_dout
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