2 floating-point status/control register (fpscr) – Renesas SH7781 User Manual
Page 163
6. Floating-Point Unit (FPU)
Rev.1.00 Jan. 10, 2008 Page 133 of 1658
REJ09B0261-0100
6.3.2
Floating-Point Status/Control Register (FPSCR)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
bit:
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
Initial value:
R
R
R
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W:
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
bit:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
Initial value:
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W:
Enable (EN)
FR
SZ
PR
DN
Flag
RM
Cause
Cause
Bit Bit
Name
Initial
Value R/W
Description
31 to 22 —
All 0
R
Reserved
These bits are always read as 0. The write value should
always be 0.
21
FR
0
R/W
Floating-Point Register Bank
0: FPR0_BANK0 to FPR15_BANK0 are assigned to
FR0 to FR15 and FPR0_BANK1 to FPR15_BANK1
are assigned to XF0 to XF15
1: FPR0_BANK0 to FPR15_BANK0 are assigned to
XF0 to XF15 and FPR0_BANK1 to FPR15_BANK1
are assigned to FR0 to FR15
20 SZ
0
R/W
Transfer
Size
Mode
0: Data size of FMOV instruction is 32-bits
1: Data size of FMOV instruction is a 32-bit register
pair
(64
bits)
For relations between endian and the SZ and PR bits,
see figure 6.5.
19 PR
0
R/W
Precision
Mode
0: Floating-point instructions are executed as
single-precision
operations
1: Floating-point instructions are executed as
double-precision operations (graphics support
instructions are undefined)
For relations between endian and the SZ and PR bits,
see figure 6.5.
18 DN
1
R/W
Denormalization
Mode
0: Denormalized number is treated as such
1: Denormalized number is treated as zero