XC886_1 Datasheet, PDF (34/144 Pages) Infineon Technologies AG – 8-Bit Single-Chip Microcontroller

XC886/888CLM
Functional Description
• Overwrite the contents of PAGE with the contents of STx, ignoring the value written
to the bit positions of PAGE
(this is done at the end of the interrupt routine to restore the previous page setting
before the interrupt occurred)
ST3
ST2
ST1
ST0
STNR
value update
from CPU
PAGE
Figure 10 Storage Elements for Paging
With this mechanism, a certain number of interrupt routines (or other routines) can
perform page changes without reading and storing the previously used page information.
The use of only write operations makes the system simpler and faster. Consequently,
this mechanism significantly improves the performance of short interrupt routines.
The XC886/888 supports local address extension for:
• Parallel Ports
• Analog-to-Digital Converter (ADC)
• Capture/Compare Unit 6 (CCU6)
• System Control Registers
Data Sheet
27
V0.9, 2006-12