7.The Real-Time Bus Monitor
The program REALTIM1.EXE in the MONTOR directory is a completely non-invasive real-time bus monitor which records activity on an I2C-bus, post-processes the data and stores the results in an ASCII file. This file can be printed out or examined with a word-processor as required. The monitor can record up to 30,000 operations on the I2C-bus.
For the real-time monitor to work correctly it must be run using an 8MHz 286 AT type computer or any faster machine (386/486 are ideal). Also, no TSR programs or background applications must be active while running the monitor.
The monitor program can write quite large data files to disc; it must be copied from the floppy disc supplied onto your hard disc before being executed.
The monitor program has to run very fast and without interruptions in order to accurately record data from the I2C-bus. To achieve this it re-vectors the normal BIOS keyboard and clock-tick interrupt routines and uses these for its own purposes. It is essential that the monitor program is exited cleanly – this is achieved by pressing any alphanumeric key on the keyboard while it is monitoring; the monitor program will restore the normal interrupts when it finishes.
Do not attempt to run the real-time monitor from any version of Windows
The following mnemonics are used by the monitor program in the ASCII file which it produces.
SaXX | Start code followed by address, acknowledged. |
SnXX | Start code followed by address, not acknowledged. |
DaXX | Data byte, acknowledged. |
DnXX | Data byte, not acknowledged. |
STOP | Stop code. |
BUS ERROR | A bus error has occurred. This is non-fatal to the monitor but a small amount of |
| data may have been lost whilst recovery was taking place. |
Note: The program REALTIM1 expects the ICA93 adapter to be configured as supplied (i.e. default base address, no interrupts). If this is not the case please refer to Section 3 of the User Manual for details of the correct link positions. The one exception is the bus pull-ups. These may be on or off on the ICA93; bus terminations must be present somewhere on the bus for it to operate. The alternative program, REALTIM2 is identical except it is for an ICA93 configured with an alternative base address of 0x312.
Revision 1.7 | Page 22 of 27 |
09/12/1999 | |
