NEC V850E/RS1, User Manual, Page: 68 / 852

68
Chapter 3 CPU Function
User’s Manual U16702EE3V2UD00
Figure 3-6: Program Status Word (PSW) Format (2/2)
(5) CALLT execution status saving registers (CTPC and CTPSW)
CTPC and CTPSW are CALLT execution status saving registers.
When the CALLT instruction is executed, the contents of the program counter (PC) are saved to
CTPC, and those of the program status word (PSW) are saved to CTPSW.
The contents saved to CTPC are the address of the instruction next to CALLT.
The current contents of the PSW 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.
Figure 3-7: CALLT Execution Status Saving Registers (CTPC and CTPSW) Format
The values of CTPC and CTPSW are restored to PC and PSW during execution of the CTRET
instruction.
Status of operation result
Flag status
Result of operation of
saturation processing
SAT OV S
Maximum positive value is exceeded. 1 1 0 7FFFFFFFH
Maximum negative value is exceeded. 1 1 1 80000000H
Positive (maximum value is not exceeded)
Holds value before
operation
0
0
Operation result itself
Negative (maximum value is not exceeded) 1
31 0
CTPC
(PC contents) 0 0
After reset
0xxxxxxxH
(x: Undefined)
26 25
0 0 0 0
31 0
CTPSW
(PSW contents) 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
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