16F628A current high during sleep

[Rubicon]

Thanks for the reply and the advice.

I don't have a schematic as yet as it's all breadboarded and constantly changing as I learn new things. I really must do one though.

One thing I don't understand is why with the exact same port settings and commands @SLEEP is 1.2mA and END is 0.4mA. Shouldn't they be the same, either both 1.2mA or both 0.4mA?

CYCLE:
CMCON=7
VRCON=%01101100 'VRCON bit7 is OFF for no current drain
TRISA = %10011
PORTA = 0
TRISB = %01000101
PORTB = %10000000
@SLEEP 'ASM Sleep
GOTO CYCLE

SHUTDOWN:
CMCON=7
VRCON=%01101100 'VRCON bit7 is OFF for no current drain
TRISA = %10011
PORTA = 0
TRISB = %01000101
PORTB = %10000000
END

Regards,

Rubicon.

[Jerson]

I am not sure if you have seen this.

Excerpt from the datasheet of PIC16F917. I am sure this applies to the 628 too though I have not checked it.

<Quote>
When the SLEEP instruction is being executed, the next
instruction (PC + 1) is pre-fetched. For the device to
wake-up through an interrupt event, the corresponding
interrupt enable bit must be set (enabled). Wake-up is
regardless of the state of the GIE bit. If the GIE bit is
clear (disabled), the device continues execution at the
instruction after the SLEEP instruction. If the GIE bit is
set (enabled), the device executes the instruction after
the SLEEP instruction, then branches to the interrupt
address (0004h). In cases where the execution of the
instruction following SLEEP is not desirable, the user
should have a NOP after the SLEEP instruction.
</quote>

Perhaps, you need to take care of this

Like this
@ sleep
@ nop
@ nop

I use this for my 628 programs and get the sleep operate correctly.

Jerson

[Rubicon]

Yes I admit to seeing that in the 16F628 datasheet and I tried a single nop without the @ after the sleep command without success. I'll put in what you suggest and see what happens today.

Thanks,

Rubicon.

[Rubicon]

Well that didn't work nor did trying it without the @. Back to looking at the pin states and doing a schematic.

Thanks for your help here. I do appreciate it.

Regards,

Rubicon.