R01UH0822EJ0100 Rev.1.00
Page 50 of 1041
Jul 31, 2019
RX13T Group
2. CPU
2.2.2.6
Backup PSW (BPSW)
The backup PSW (BPSW) is provided to speed up response to interrupts.
After a fast interrupt has been generated, the contents of the processor status word (PSW) are saved in the BPSW. The
allocation of bits in the BPSW corresponds to that in the PSW.
2.2.2.7
Fast Interrupt Vector Register (FINTV)
The fast interrupt vector register (FINTV) is provided to speed up response to interrupts.
The FINTV register specifies a branch destination address when a fast interrupt has been generated.
2.2.2.8
Floating-Point Status Word (FPSW)
b31
b0
Value after reset:
Undefined
b31
b0
Value after reset:
Undefined
b31
b30
b29
b28
b27
b26
b25
b24
b23
b22
b21
b20
b19
b18
b17
b16
FS
FX
FU
FZ
FO
FV
—
—
—
—
—
—
—
—
—
—
Value after reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
—
EX
EU
EZ
EO
EV
—
DN
CE
CX
CU
CZ
CO
CV
RM[1:0]
Value after reset:
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b1, b0
Floating-Point Rounding-Mode
Setting
b1 b0
0 0: Rounding towards the nearest value
0 1: Rounding towards 0
1 0: Rounding t∞
1 1: Rounding towards –∞
R/W
b2
Invalid Operation Cause Flag
0: No invalid operation has been encountered.
1: Invalid operation has been encountered.
R/(W)
*
b3
Overflow Cause Flag
0: No overflow has occurred.
1: Overflow has occurred.
R/(W)
*
b4
Division-by-Zero Cause Flag
0: No division-by-zero has occurred.
1: Division-by-zero has occurred.
R/(W)
*
b5
Underflow Cause Flag
0: No underflow has occurred.
1: Underflow has occurred.
R/(W)
*
b6
Inexact Cause Flag
0: No inexact exception has been generated.
1: Inexact exception has been generated.
R/(W)
*
b7
Unimplemented Processing Cause
Flag
0: No unimplemented processing has been encountered.
1: Unimplemented process has been encountered.
R/(W)
*