NEC PD754144 - Manual (Page 59)

CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP
59 User’s Manual U10676EJ3V0UM
Figure 3-7. µPD754244 I/O Map (8/8)
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
FF0H Unmounted
to
FF2H
FF3H Port 3 (PORT3) R/W –
fmem.bit
pmem.@L
FF4H Unmounted
FF5H
FF6H Port 6 (PORT6) R/W – fmem.bit
pmem.@L
FF7H Note 1 R –
FF8H R/W – A write to an unmounted area is invalid, and
the read value is undefined.
FF9H Unmounted
to
FFFH
Notes 1. KR4 to KR7 can only be read in 1-bit units. In 4-bit parallel input, PORT7 is used for specification.
2. These are not registered as reserved words.
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Port 7 (PORT7)
KR7 KR6 KR5 KR4
Port 8 (PORT8)
– – – P80 Note 2