CHAPTER 3 CPU FUNCTION
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User’s Manual U15195EJ5V0UD
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Note
During saturated operation, the saturated operation results are determined by the contents of the OV
flag and S flag. The SAT flag is set (to 1) only when the OV flag is set (to 1) during saturated operation.
Flag status
Operation result status
SAT OV S
Saturated
operation result
Maximum positive value exceeded
1
1
0
7FFFFFFFH
Maximum negative value exceeded
1
1
1
80000000H
Positive (maximum value not exceeded)
0
Negative (maximum value not exceeded)
Holds value
before operation
0
1
Actual operation
result
(5) CALLT execution status saving registers (CTPC, CTPSW)
There are two CALLT execution status saving registers, CTPC and CTPSW.
When the CALLT instruction is executed, the contents of the program counter (PC) are saved to CTPC, and
the program status word (PSW) contents are saved to CTPSW.
The contents saved to CTPC consist of the address of the next instruction after the CALLT instruction.
The current PSW contents are saved to CTPSW.
Bits 31 to 26 of CTPC and bits 31 to 8 of CTPSW are reserved (fixed to 0) for future function expansion.
31
0
CTPC
(PC contents saved)
0
0
After reset
0xxxxxxxH
(x: Undefined)
26 25
0 0 0 0
31
0
CTPSW
(PSW contents saved)
0
0
After reset
000000xxH
(x: Undefined)
8
0 0 0 0
0
0
0 0 0 0
0
0
0 0 0 0
0
0
0 0 0 0
7
Содержание PD703114
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