r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 166

• Manufacturer Part Number: r8a77850anbg
• Description: Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

6. Floating-Point Unit (FPU)
Table 6.3
6.3.3
Information is transferred between the FPU and CPU via FPUL. FPUL is a 32-bit system register
that is accessed from the CPU side by means of LDS and STS instructions. For example, to
convert the integer stored in general register R1 to a single-precision floating-point number, the
processing flow is as follows:
Rev.1.00 Jan. 10, 2008 Page 136 of 1658
REJ09B0261-0100
Cause
Enable
Flag
R1 → (LDS instruction) → FPUL → (single-precision FLOAT instruction) → FR1
Field Name
FPU exception
cause field
FPU exception
enable field
FPU exception
flag field
Floating-Point Communication Register (FPUL)
Bit Allocation for FPU Exception Handling
FPU
Error (E)
Bit 17
None
None
Invalid
Operation (V)
Bit 16
Bit 11
Bit 6
Bit 15
Division
by Zero (Z)
Bit 10
Bit 5
Overflow
(O)
Bit 14
Bit 9
Bit 4
Underflo
w (U)
Bit 13
Bit 8
Bit 3
Inexact
(I)
Bit 12
Bit 7
Bit 2