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31
PSW
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NP EP ID SAT CY OV S Z
Bit Position
Bit Name
7
NP
Indicates that non-maskable interrupt servicing is in progress. When the non-maskable
interrupt is acknowledged, this flag is set (1) to disable multiple interrupts.
0: Non-maskable interrupt servicing is not in progress
1: Non-maskable interrupt servicing is in progress
6
EP
Indicates that exception processing is in progress. This flag is set (1) when an exception is
generated. Interrupt requests are acknowledged even if this bit is set.
0: Exception processing is not in progress
1: Exception processing is in progress
5
ID
Indicates whether or not maskable interrupt requests can be acknowledged.
0: Interrupts are enabled
1: Interrupts are disabled
4
SAT
Indicates that the calculation result of a saturated calculation processing instruction
overflowed and the calculation result is saturated. This flag, which is called the saturation
flag, is set (1) when the calculation result of a saturated calculation instruction is saturated,
and it is not cleared (0) even if the calculation results of subsequent instructions are not
saturated. When this flag is cleared (0), data is loaded in the PSW. This bit is neither set (1)
nor cleared (0) by a general arithmetic calculation.
0: It is not saturated
1: It is saturated
3
CY
Indicates whether or not a carry or borrow occurred in the calculation result.
0: No carry or borrow occurred
1: A carry or borrow occurred
2
OV
Indicates whether or not an overflow occurred during the calculation.
0: No overflow occurred
1: An overflow occurred
1
S
Indicates whether or not the calculation result is negative.
0: The calculation result is positive or zero
1: The calculation result is negative
0
Z
Indicates whether or not the calculation result is zero.
0: The calculation result is not zero
1: The calculation result is zero
CHAPTER 3 CPU
Figure 3-4. Program Status Word (PSW)
Preliminary User's Manual A14874EJ3V0UM
8 7 6 5 4 3 2 1 0
Function
After reset
00000020H
57
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