'Intrusive read'

[andreasbuehler19]

Posted on June 07, 2005 at 06:33

'Intrusive read'

[andreasbuehler19]

Posted on June 06, 2005 at 11:39

Hallo,

I want to debug a programme using STDV7 (V3.1.1), Cosmic-Compiler and MCU ST72F521R9. For that I want to see the flags of the Timer A statusregister (TACSR). But instead seeing a value I get only the message: 'Intrusive Read' Is that a normal state or will there be something wrong. Thanks abue

[fggnrc]

Posted on June 06, 2005 at 12:36

abue,

this message reminds you that whenever this register is read (e.g. to display its value), a side effect happens. This effect may clear a pending interrupt flag (e.g. an input capture event) and this may result in an unexpected behaviour... Please, see the microcontroller datasheet for the related details. Regards, EtaPhi

[alain2399]

Posted on June 07, 2005 at 06:33

If you search for ''intrusive'' in the STVD7 online help you will find:

============================== Forced read of status registers Values of status register items in the Peripheral Registers window are not normally available-beside each item, you will see the message ''Intrusive read'' indicating that reading the value of these registers could intrude upon the normal running of the program, and give rise to unpredictable results. However, if you absolutely must know the value of a particular status register item, select the item with the mouse and click-right to bring up the contextual menu, as shown above. You will then have access to an additional option -- the Forced Read option. Choosing this option will allow an intrusive read of the status register. A dialog box will appear as below, warning you of the possibility of unpredictable consequences, and giving the value of the status register. ========================================== Best regards, Alain