Direct Page Register (Dpr) - Fujitsu MB90480 Series Hardware Manual

CHAPTER 2 CPU
2.3.6

Direct Page Register (DPR)

This section explains the direct page register (DPR) functions.
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Direct page register (DPR) <Initial value: 01
The direct page register (DPR) specifies, as shown in Figure 2.3-11, addresses 8 to 15 of an
instruction operand in the direct addressing mode. DPR has a length of 8 bits, and is initialized
to 01 by a reset. It also allows reading and writing by instructions.
H
Figure 2.3-11 illustrates the generation of a physical address in the direct addressing mode.
Figure 2.3-11 Generating a physical address in direct addressing mode
DTB register
24-bit physical address
38
MSB
>
H
DPR register Direct address in instruction
LSB