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Stack Structure: When the program counter (PC) is pushed onto the stack in a subroutine call,
and the PC, condition-code register (CCR), and extended control register (EXR) are pushed onto
the stack in exception handling, they are stored as shown in figure 2-3. When EXR is invalid, it is
not pushed onto the stack. For details, see section 4, Exception Handling.
SP
(a) Subroutine Branch
Notes: 1.
When EXR is not used it is not stored on the stack.
2.
SP when EXR is not used.
3.
Ignored when returning.
(2) Advanced Mode
Address Space: Linear access is provided to a 16-Mbyte maximum address space (architecturally
a maximum 16-Mbyte program area and a maximum 4-Gbyte data area, with a maximum of 4
Gbytes for program and data areas combined).
Extended Registers (En): The extended registers (E0 to E7) can be used as 16-bit registers, or as
the upper 16-bit segments of 32-bit registers or address registers.
Instruction Set: All instructions and addressing modes can be used.
26
PC
(16 bits)
Figure 2-3 Stack Structure in Normal Mode
SP
Reserved
*2
(SP
)
(16 bits)
(b) Exception Handling
*1
EXR
*1,*3
CCR
*3
CCR
PC
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