MSP430 / Interrupts / Status Register

try twice...

Hello to all,

I have to programm a TI MSP430 in Forth. My problem is, that I'm not able
to write in the status register or in IE1. I can write in other control
registers like the ADC12CTL1 e.g. but i can't handle the interrupts.

I'm using the following forth code to call the command "DINT":

code /DisableInt
DINT
RET
end-code

It also dosn't work when I'm using 

code /DisableInt
8 # SR & bic.b
RET
end-code

And there is no fault or problem when I want to write anything to IE1.
There's just no change in IE1 after writing.

Does anybody knows what's my mistake? What do I have to attend before
writing to IE1 or before using the DINT-Command?

Thank you,

Chris

In article 
<3b771918a4641563fe3606c72aa6a4de@localhost.talkaboutelectronicequipment
.com>, christian@nospam says...
> try twice...
> 
> Hello to all,
> 
> I have to programm a TI MSP430 in Forth. My problem is, that I'm not able
> to write in the status register or in IE1. I can write in other control
> registers like the ADC12CTL1 e.g. but i can't handle the interrupts.
> 
> I'm using the following forth code to call the command "DINT":
> 
> code /DisableInt
> DINT
> RET
> end-code
> 
> It also dosn't work when I'm using 
> 
> code /DisableInt
> 8 # SR & bic.b
> RET
> end-code
> 
> And there is no fault or problem when I want to write anything to IE1.
> There's just no change in IE1 after writing.
> 
> Does anybody knows what's my mistake? What do I have to attend before
> writing to IE1 or before using the DINT-Command?
> 
> Thank you,
> 
> Chris
> 
> 
> 

My Forth assembly is a little rusty,
but it appears you are ANDing the immediate value 8 with the ADDRESS of 
SR. Thus, there is an argument missing for BIC.B, which requires a bit 
number and a register address.

Regardless, are you trying to use this word inside an interrupt handler?
SR might be being restored to whatever its contents were before the 
interrupt was taken when RETI is called, overwriting your change...

--Gene

Hi,

Thank you. The problem is that GIE is set to "0" only in the code
structure. After "END-CODE" it is reset to "1". It's set to "1" if there's
no "RET", too. Do you know a solution for my problem?
Is there any other possibility for writing to SR without Assembler?

kind regards, 

Chris

In article <01c9f13a9af87356ac2005dfef1d0fc3
@localhost.talkaboutelectronicequipment.com>, christian@nospam says...
> Hi,
> 
> Thank you. The problem is that GIE is set to "0" only in the code
> structure. After "END-CODE" it is reset to "1". It's set to "1" if there's
> no "RET", too. Do you know a solution for my problem?
> Is there any other possibility for writing to SR without Assembler?
> 
> kind regards, 
> 
> Chris

There's a couple of possibilities:
There may be a variant form of END-CODE, that does not attempt to 
restore the status register.  If not, you could write your own.
Disassemble END-CODE, remove the code that is restoring SR, and
create END-CODE-NO-SR, or whatever.
There is likely a word for register access that can be called to
modify SR without using CODE.

--Gene