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NEC PD754144 User Manual

Page 51

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CHAPTER 3 FEATURES OF ARCHITECTURE AND MEMORY MAP

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User’s Manual U10676EJ3V0UM

Figure 3-7 shows the I/O map of the

µPD754244.

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:

Read only

W:

Write only

Number of bits that can be manipulated .......... Indicates the bit units in which the hardware unit in question can

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

manipulated, refer to Remarks.

– : Cannot be manipulated in specified units (1, 4, or 8 bits).

• Bit manipulation addressing ............................... Indicates a bit manipulation addressing mode that can be used to

manipulate the hardware unit in question in 1-bit units

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