NEC PD754144 User Manual page 51

CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP
Figure 3-7 shows the I/O map of the µ PD754244.
The meanings of the symbols shown in this figure are as follows.
• Symbol ............ Name indicating the address of an internal hardware unit
Can be written in operands of instructions
• R/W ................. Indicates whether the hardware unit in question can be read or written
R/W: Read/write
R:
W:
• Number of bits that can be manipulated .......... Indicates the bit units in which the hardware unit in question can
• Bit manipulation addressing ............................... Indicates a bit manipulation addressing mode that can be used to
Read only
Write only
be manipulated
: Can be manipulated in specified units (1, 4, or 8 bits)
: Only some bits can be manipulated. For the bits that can be
– : Cannot be manipulated in specified units (1, 4, or 8 bits).
manipulate the hardware unit in question in 1-bit units
User's Manual U10676EJ3V0UM
manipulated, refer to Remarks.
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