Epson S1C33 Series, Руководство по основам

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6 FUNCTIONS
56 EPSON S1C33 FAMILY C33 PE CORE MANUAL
6 . 3 . 9 Undefined Instruction Exception
When an instruction, which does not exist in the C 33 PE instruction set, is executed, an undefined instruction
exception occurs. The object code is loaded into the 16 low-order bits of the IDIR register and is processed similar
to the
nop
instruction. In this case, the PC value that is saved into the stack by the exception processing is the
instruction address that follows the undefined instruction executed.
Address TTBR +
12 is used to store the undefined instruction exception vector.
6 . 3 . 10
ext
Exception
If three or more
ext
instructions are described sequentially, an
ext
exception occurs when the third
ext
instruction is detected. In this case, the PC value that is saved into the stack by the exception processing is the first
ext
instruction address.
Address TTBR + 8 is used to store the
ext
exception vector.
When an instruction, which does not support the extension in the
ext
instruction, follows an
ext
, the
ext
instruction will be executed as a
nop
instruction.