NEC PD754144 - Manual (Page 57)

CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP
57 User’s Manual U10676EJ3V0UM
Figure 3-7. µPD754244 I/O Map (6/8)
Hardware name (symbol)
Number of bits that
Bit
Address R/W
can be manipulated
manipulation Remarks
b3 b2 b1 b0 1-bit 4-bit 8-bit
addressing
FD0H Unmounted
to
FD3H
FD4H Programmable threshold port (PTH0) R – mem.bit
FD5H Unmounted
FD6H R/W – – mem.bit A write to bit 4 or bit 5 is invalid, and the read
Programmable threshold port mode register (PTHM) value is undefined.
FD8H Unmounted
to
FDBH
FDCH
PO3 Note – – –
R/W – – – A write to an unmounted area is invalid, and
Pull-up resistor specification register group A (POGA) the read value is undefined.
– PO6 Note – –
FDEH
– – – PO8 Note
R/W – – –
Pull-up resistor specification register group B (POGB)
– – – –
Note These are not registered as reserved words.
................................................................................
................................................................................
................................................................................
................................................................................
................................................................................
PTHM3 Note PTHM2 Note PTHM1 Note PTHM0 Note
PTHM7 Note PTHM6 Note – –
....................................................................