Operation Of The Chip Selection Facility - Fujitsu F2MC-16LX Hardware Manual

CHAPTER 23 CHIP SELECTION FACILITY

23.3 Operation of the Chip Selection Facility

This section describes the operations of the chip selection facility.
I Outline of operations
When the CPU accesses program or data, the chip selection facility is activated if a match
between the upper 8 bits of an address and CAR0/1/2/3 is detected. Addresses for which the
corresponding bits in CSM0/1/2/3 are set to "1" are ignored, and decoding becomes possible for
an area from 64 KB to 16 MB.
During internal accesses (access to the I/O area, the built-in RAM, or the built-in ROM), the chip
selection facility is not active.
I Example of using the chip selection facility
Figure 23.3-1 "Example of using the chip selection facility" shows an example of using the chip
selection facility.
[Example 1]
[Example 2]
446
Figure 23.3-1 Example of using the chip selection facility
Address 11111110
Matching
CMR0 00000000
CAR0 11111110
Address 11111110 XXXXXXXX XXXXXXXX FEXXXXXXH
Matching
CMR0 00001111
CAR0 11111010
XXXXXXXX XXXXXXXX FEXXXXXXH
CS0 active
CS0 active