Asm sleep - pbp sleep

[richard]

your code is an uncompilable snippet so its hard to know whats going on


there are issues here

@    MOVF BAUDCON,0      ‘Is RCIDL idel?  Set for Idel    	‘For testing               
@    MOVWF _Avar     	‘For testing                   				
    Avar=Avar dig 6  		‘For testing

what bank is baudcon in ?
what bank is Avar in ?
from the looks of it Avar must be byte , how can it ever have a Dig 6

whats wrong with one of these ,one of them will produce efficient code i'm sure

if baudcon & 64 then
avar=1
else
avar=0
endif

or

avar=baudcon.6

or

avar=(baudcon&64) >>6

[sayzer]

Here is something from me:

1. Leave the RX pin unconnected for testing. Check the pin state. Does it stay low or high? If it is high and you get int at high already, then it never sleeps.
2. IF all ok, then before sleep instructon, disable GIE and PEIE first. Disable eusart module. Then re-enable it. clear the flags. Then enable GIE, PEIE and lastly usart int bit. Make sure usart flag is cleared, and Usart int bit enabled at the last just before SLEEP command.
3. There should be at least two NOP() immediately after SLEEP.
4. If there are some other ints in your code not shown here, than they may be the cause of wake up. Remember, Most of the ext int sources wake the device up eventhough you do not care for them. Make sure you disable all other ext int sources (if you are using any) before SLEEP.

[richard]

3. There should be at least two NOP() immediately after SLEEP.

not as i read the data sheet

When the SLEEP instruction is being executed, the next
instruction (PC + 1) is prefetched. For the device to
wake-up through an interrupt event, the corresponding
interrupt enable bit must be enabled. Wake-up will
occur regardless of the state of the GIE bit. If the GIE
bit is disabled, the device continues execution at the
instruction after the SLEEP instruction. If the GIE bit is
enabled, the device executes the instruction after the
SLEEP instruction, the device will call the Interrupt Service
Routine. In cases where the execution of the
instruction following SLEEP is not desirable, the user
should have a NOP after the SLEEP instruction.

[Ioannis]

One NOP is enough and should be a good practice to have one in any case. After all a NOP delay is too small to create any short of problem.

Ioannis

[sayzer]

Yes, I checked it again. For some reason I remember to have two NOPs. Sorry for that. Have one or three. It is up to you.

[Ioannis]

I rephrase: at least one NOP.

You may have as many as you want of course. Will not argue that. Still, I do not know which case(s) will not need the NOP, so put it there in any case!

Ioannis

[MOUNTAIN747]

Yes, I checked it again. For some reason I remember to have two NOPs. Sorry for that. Have one or three. It is up to you.

So I've run all the test Sayzer has suggested. No changes. I then strip code to a couple of lines. I have done this on multipal 1936 and different boards.

Asm
 __config _CONFIG1,_FOSC_INTOSC & _CLKOUTEN_OFF & _MCLRE_ON & _BOREN_OFF & _WDTE_OFF & _FCMEN_OFF & _CP_OFF & _CPD_OFF & _IESO_OFF
 __config _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_ON & _BORV_LO & _LVP_OFF
endasm  
define OSC 8
    OSCCON=%01110000   ;1110=8Mhz                                                 
    ANSELA=$0   
    ANSELB=$0    
    ADCON0=$0
    PortA=0
    PortB=0                                      
    PortC=0 
    TrisA=%00000001                                                                                
    TrisB=%00001001        
    TrisC=%00000000   
    Avar    var byte
    Bvar    var byte
    Cvar    var byte 
    
SleepMode:
ASM
;    BTFSS   BAUDCON,RCIDL  ;Check for High, no receive in progress 
;    GOTO $-1                     ;return to previous line
;    BSF BAUDCON,WUE        ;Wake on Rx from Master
;    BSF PORTA,1            ;LED
   
    SLEEP
    BSF  PORTC,1   ;LED 
    nop
    nop
    nop                   .
ENDASM

SLEEP is the first command after which my LED flashes apx. every 2.14seconds.
I then expand the code.

SleepMode:
ASM
;    BTFSS   BAUDCON,RCIDL  ;Check for High, no receive in progress 
;    GOTO $-1                     ;return to previous line
               
    BSF BAUDCON,WUE        ;Wake on Rx from Master
    BSF PORTA,1    ;LED 
    SLEEP
    BSF  PORTC,1   ;LED 
    nop
    nop
    nop                   .
ENDASM
       END

I run the code and LED A.1 is on and LED C.1 is blinding every 2.14sec.
I then expand the code.

SleepMode:
ASM
    BTFSS   BAUDCON,RCIDL  ;Check for High, no receive in progress 
    GOTO $-1                     ;return to previous line
    BSF BAUDCON,WUE        ;Wake on Rx from Master
    BSF PORTA,1            ;LED  
    SLEEP
    BSF  PORTC,1   ;LED 
    nop
    nop
    nop                    ; Should be in sleep for 10sec.
ENDASM

I run the code and No LED comes on. The program is stuck in the loop BTFSS BAUDCON, RCIDL & GOTO $-1. This is a HARDWARE RESET not caused by any of my code unless something in the configs are at falt. Threre are no interrupts as I have tested all flag bits i can think of. Rx stays LOW. No com is connected to the board. RCIDL should be HIGH but it is not.
CONFIGS !!! Next round of testing.

[richard]

its all the same problem
what bank is baudcon in?
what bank is porta or portc in ?

ASM
BTFSS BAUDCON,RCIDL ;Check for High, no receive in progress
GOTO $-1 ;return to previous line
BSF BAUDCON,WUE ;Wake on Rx from Master
BSF PORTA,1 ;LED
SLEEP
BSF PORTC,1 ;LED
nop
nop
nop ; Should be in sleep for 10sec.
ENDASM