How to distinguish a reset_cpu() and a power up restart

[Ivar Boer]

Hello programmers,

Iam using a PIC16F877A processor.
I have implemented the function reset_cpu(). This function is translated in assmble code goto 0x000. After this function I want to do a restart cause check with the function restart_cause(). If both bits (!TO) and (!PD) are 1 a power up occured.

When a power up occured my Time Counters have to be set to 0, otherwise not.

Now the problem is that the restart_cause() function always sees a power up (I think this status of the last power up), which means the reset_cpu() function does not infect bits (!TO) and (!PD).

Can someone help to distinguish these types of restarts from eachother in a nice way.

Thanks!
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This message was ported from CCS's old forum
Original Post ID: 11824

[Tomi]

I use the PowerOn bit which is cleared only if the PIC is powered on. You must set this bit by software after reset (see Chapter 2.2.2.8 for details):
#byte PCON = 0x8E

if (!bit_test(PCON,1)) {
DoPowerUp(); // what to do in case of power-up
bit_set(PCON,1);
}


Then I implement a "full-restart" as:
bit_clear(PCON,1); // force PIC to execute power-up function
while (1) ; // watchdog does the job

:=Hello programmers,
:=
:=Iam using a PIC16F877A processor.
:=I have implemented the function reset_cpu(). This function is translated in assmble code goto 0x000. After this function I want to do a restart cause check with the function restart_cause(). If both bits (!TO) and (!PD) are 1 a power up occured.
:=
:=When a power up occured my Time Counters have to be set to 0, otherwise not.
:=
:=Now the problem is that the restart_cause() function always sees a power up (I think this status of the last power up), which means the reset_cpu() function does not infect bits (!TO) and (!PD).
:=
:=Can someone help to distinguish these types of restarts from eachother in a nice way.
:=
:=Thanks!
___________________________
This message was ported from CCS's old forum
Original Post ID: 11827