NS32FX161-15 Datasheet, PDF (13/102 Pages) National Semiconductor (TI) – Advanced Imaging/Communication Signal Processors

2 0 Architectural Description (Continued)
Following Index Bytes come any displacements (addressing
constants) or immediate values associated with the select-
ed addressing modes Each Disp lmm field may contain
one of two displacements or one immediate value The size
of a Displacement field is encoded within the top bits of that
field as shown in Figure 2-19 with the remaining bits inter-
preted as a signed (two’s complement) value The size of an
immediate value is determined from the Opcode field Both
Displacement and Immediate fields are stored most-signifi-
cant byte first Note that this is different from the memory
representation of data (Section 2 2)
Some instructions require additional ‘‘implied’’ immediates
and or displacements apart from those associated with ad-
dressing modes Any such extensions appear at the end of
the instruction in the order that they appear within the list of
operands in the instruction definition (Section 2 4 3)
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FIGURE 2-18 Index Byte Format
Note Dashed lines indicate information copied to register during transfer of control between modules
FIGURE 2-16 NS32FX164 Run-Time Environment
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FIGURE 2-17 General Instruction Format
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