Samsung S3C2440A User Manual

Page 115

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ARM INSTRUCTION SET

S3C2440A RISC MICROPROCESSOR

3-58

UNDEFINED INSTRUCTION

The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction format is shown in Figure 3-28.

31

27

Cond

28

25 24

011

xxxxxxxxxxxxxxxxxxxx

1

xxxx

5 4 3

0

Figure 3-28. Undefined Instruction

If the condition is true, the undefined instruction trap will be taken.

Note that the undefined instruction mechanism involves offering this instruction to any coprocessors which may be
present, and all coprocessors must refuse to accept it by driving CPA and CPB HIGH.


INSTRUCTION CYCLE TIMES

This instruction takes 2S + 1I + 1N cycles, where S, N and I are defined as sequential (S-cycle), non-sequential (N-
cycle), and internal (I-cycle).


ASSEMBLER SYNTAX

The assembler has no mnemonics for generating this instruction. If it is adopted in the future for some specified
use, suitable mnemonics will be added to the assembler. Until such time, this instruction must not be used.

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