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Renesas SH7781 User Manual

Page 64

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2. Programming Model

Rev.1.00 Jan. 10, 2008 Page 34 of 1658
REJ09B0261-0100

Bit Bit

Name

Initial
Value R/W Description

27 to 16 —

All 0

R

Reserved

For details on reading/writing this bit, see General
Precautions on Handling of Product.

15

FD

0

R/W

FPU Disable Bit

When this bit is set to 1 and an FPU instruction is not in
a delay slot, a general FPU disable exception occurs.
When this bit is set to 1 and an FPU instruction is in a
delay slot, a slot FPU disable exception occurs. (FPU
instructions: H'F*** instructions and LDS (.L)/STS(.L)
instructions using FPUL/FPSCR)

14 to 10 —

All 0

R

Reserved

For details on reading/writing this bit, see General
Precautions on Handling of Product.

9 M

0 R/W

M

Bit

Used by the DIV0S, DIV0U, and DIV1 instructions.

8 Q

0 R/W

Q

Bit

Used by the DIV0S, DIV0U, and DIV1 instructions.

7 to 4

IMASK

1111

R/W

Interrupt Mask Level Bits
An interrupt whose priority is equal to or less than the
value of the IMASK bits is masked. It can be chosen by
CPU operation mode register (CPUOPM) whether the
level of IMASK is changed to accept an interrupt or not
when an interrupt is occurred. For details, see appendix
A, CPU Operation Mode Register (CPUOPM).

3, 2

All 0

R

Reserved

For details on reading/writing this bit, see General
Precautions on Handling of Product.

1 S

0 R/W

S

Bit

Used by the MAC instruction.

0 T

0 R/W

T

Bit

Indicates true/false condition, carry/borrow, or
overflow/underflow.

For details, see section 3, Instruction Set.