Bascom PUSHALL

 

I ran into a conundrum when trying to get my UART0 sniffer program going.
After the BASCOM PUSHALL statement, R24 was always zero.

I compiled this code snipit and then disassembled it to see what PUSHALL did.

Code:

Pushall  ' <-- Seems to have strange effects when used here Franks_Push: !PUSH r16 !PUSH r24 !PUSH r25 !PUSH r26 !PUSH r27 !PUSH r28 !PUSH r29 !PUSH r30 !PUSH r31

Code:

51:       Pushall  ' <-- Seems to have strange effects when used here +000000BB:   920F        PUSH      R0             Push register on stack +000000BC:   921F        PUSH      R1             Push register on stack +000000BD:   922F        PUSH      R2             Push register on stack +000000BE:   923F        PUSH      R3             Push register on stack +000000BF:   924F        PUSH      R4             Push register on stack +000000C0:   925F        PUSH      R5             Push register on stack +000000C1:   927F        PUSH      R7             Push register on stack +000000C2:   92AF        PUSH      R10            Push register on stack +000000C3:   92BF        PUSH      R11            Push register on stack +000000C4:   930F        PUSH      R16            Push register on stack +000000C5:   931F        PUSH      R17            Push register on stack +000000C6:   932F        PUSH      R18            Push register on stack +000000C7:   933F        PUSH      R19            Push register on stack +000000C8:   934F        PUSH      R20            Push register on stack +000000C9:   935F        PUSH      R21            Push register on stack +000000CA:   936F        PUSH      R22            Push register on stack +000000CB:   937F        PUSH      R23            Push register on stack +000000CC:   938F        PUSH      R24            Push register on stack +000000CD:   939F        PUSH      R25            Push register on stack +000000CE:   93AF        PUSH      R26            Push register on stack +000000CF:   93BF        PUSH      R27            Push register on stack +000000D0:   93CF        PUSH      R28            Push register on stack +000000D1:   93DF        PUSH      R29            Push register on stack +000000D2:   93EF        PUSH      R30            Push register on stack +000000D3:   93FF        PUSH      R31            Push register on stack +000000D4:   B78F        IN        R24,0x3F       In from I/O location +000000D5:   938F        PUSH      R24            Push register on stack +000000D6:   B78B        IN        R24,0x3B       In from I/O location +000000D7:   938F        PUSH      R24            Push register on stack +000000D8:   2788        CLR       R24            Clear Register +000000D9:   BF8B        OUT       0x3B,R24       Out to I/O location Franks_Push: +000000DA:   930F        PUSH      R16            Push register on stack +000000DB:   938F        PUSH      R24            Push register on stack +000000DC:   939F        PUSH      R25            Push register on stack +000000DD:   93AF        PUSH      R26            Push register on stack +000000DE:   93BF        PUSH      R27            Push register on stack +000000DF:   93CF        PUSH      R28            Push register on stack +000000E0:   93DF        PUSH      R29            Push register on stack +000000E1:   93EF        PUSH      R30            Push register on stack +000000E2:   93FF        PUSH      R31            Push register on stack

As one can see, R24 is not preserved by the PUSHALL statement. How interesting.

DISASSEMBLING:
I found the article about using AVR studio to disassembled code.
' https://www.mcselec.com/index2.php?option=com_forum&Itemid=59&page=viewtopic&t=15283&highlight=obj
I gave up trying to get microchip studio 7.0 and downloaded Atmel AVR studio 4.19
So straightforward as described in the article.