k4 processor or any hc11

[bat]

In the K4 processor, how do I find the Xbit. I find all kinds of info that mentions the Xbit but never where it is located.Like the register or what bit is in the register.I have looked in all the registers and have never found a bit called the Xbit.  Its never called the Xbit in the registers. I have been able to use the Xirq pin, but only by using the TAP instruction.The TAP instruction clears the Xbit.

If no one knows about the K4 processor,  Where can I find it in any other HC11 processor.

Thanks for any help

BAT

[bat]

I really appreciate your info. I will take a look.

Thanks

BAT

[kef]

It's in CPU CCR register, bit6 of CCR, which is called X interrupt mask. TAP (transfer A-register to CCR register) instruction will clear X only in case bit6 of A register was '0'. Have a look at HC11 reference manual, Section 6 CPU, 6.3 Programmer's Model and so on:

http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC11RM.pdf