Section 3 Floating-Point Unit (FPU)
R01UH0134EJ0400 Rev. 4.00 Page 101 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
3.3 Register Descriptions
3.3.1 Floating-Point Registers
Figure 3.4 shows the floating-point register configuration. There are sixteen 32-bit floating-point
registers FPR0 to FPR15, referenced by specifying FR0 to FR15, DR0/2/4/6/8/10/12/14. The
correspondence between FRPn and the reference name is determined by the PR and SZ bits in
FPSCR. Refer figure 3.4.
1. Floating-point registers, FPRi (16 registers)
FPR0 to FPR15
2. Single-precision floating-point registers, FRi (16 registers)
FR0 to FR15 indicate FPR0 to FPR15
3. Double-precision floating-point registers or single-precision floating-point vector registers in
pairs, DRi (8 registers)
A DR register comprises two FR registers.
DR0 = {FR0, FR1}, DR2 = {FR2, FR3}, DR4 = {FR4, FR5}, DR6 = {FR6, FR7},
DR8 = {FR8, FR9}, DR10 = {FR10, FR11}, DR12 = {FR12, FR13}, DR14 = {FR14, FR15}
FPR0
FPR1
FPR2
FPR3
FPR4
FPR5
FPR6
FPR7
FPR8
FPR9
FPR10
FPR11
FPR12
FPR13
FPR14
FPR15
FR0
FR1
FR2
FR3
FR4
FR5
FR6
FR7
FR8
FR9
FR10
FR11
FR12
FR13
FR14
FR15
DR0
DR2
DR4
DR6
DR8
DR10
DR12
DR14
Transfer instruction case: FPSCR.SZ = 0 FPSCR.SZ = 1
Operation instruction case: FPSCR.PR = 0 FPSCR.PR = 1
Register name
Reference name
Figure 3.4 Floating-Point Registers