Fujitsu F2MC-16LX Hardware Manual page 463

I Notes on using the chip selection facility
• The CS0 pin always becomes active if used in external vector mode. In the address space
F00000 to FFFFFF (1 MB), which is the initial value, always use this pin only for accesses to
program ROM, since the corresponding decode signal will be output immediately after a
reset. In this case, the active level of the CS0 pin is set to "L", and "H" is output at reset. In
internal vector mode, this pin, like the CS3-1 pins, is used as a general-purpose port.
Therefore, switch to the output state after the corresponding settings have been made.
• Only enable output after the settings of the chip selection area register, mask register, and
active level register have been made.
• Note that, since the chip selection output is shared with pins P90 to P93, chip selection
output will not be available while the resource assigned to this pin is in use.
• If the pin is set to the hold state when the external bus is used, output is disabled and the pin
is set to high impedance mode. In these cases, always set the shared general-purpose port
to act as an input.
• In sleep or stop mode, the chip selection facility is not active. Note that it cannot be used by
the built-in DMA at these times.
CHAPTER 23 CHIP SELECTION FACILITY
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