Hi all,
I am working on MC9S12NE64 microcontroller.
I am using it in Normal Expanded Wide mode where in my external memory starts from 0x208000. Corresponding PPAGE register value is 20. EMK bit in mode register is set.
I am booting as Normal single chip mode and then putting my processor in Normal Expanded Wide.
For this I added startup code as below:
************************************************************************
LDD #$0CE2
STD $0A
LDAA #$01
STAA $13
LDAA #$00
STAA $0E
************************************************************************
The way I am trying to write on external memory is as follow.
************************************************************************
unsigned int *far p=(unsigned int *far)(0x208000);
while(1)
{
*p=0x5555;
}
************************************************************************
I am expecting PPAGE value should reflect on XADD19 to XADD14. When I probed XADD19 pin on oscilloscope, I observed that it is continuously low, which is not correct. Instead I am getting activity on XADD18.
Please let me know if I am missing anything.
Thanks and Regards,
Shyam