![Xilinx Virtex-II Pro PPC405 Скачать руководство пользователя страница 87](http://html1.mh-extra.com/html/xilinx/virtex-ii-pro-ppc405/virtex-ii-pro-ppc405_user-manual_3410279087.webp)
March 2002 Release
395
Virtex-II Pro™ Platform FPGA Documentation
1-800-255-7778
Integer Instructions
R
Divide Instructions
shows the PowerPC
integer-divide
instructions. Only the low-32 bits of the
quotient are returned. The remainder is not supplied as a result of executing these
instructions. For each type of instruction shown, the “Operation” column indicates the
divide-operation performed. The column also shows, on an instruction-by-instruction
basis, how the XER and CR registers are updated (if at all).
Logical Instructions
The logical instructions perform bit operations on the 32-bit operands. If an immediate
value is specified as an operand, the processor either zero-extends or left-shifts it prior to
performing the operation, depending on the instruction. If the instruction has the record
(Rc) bit set to 1 in the instruction encoding, CR0 (CR[0:3]) is updated to reflect the result of
the operation. A set Rc bit is indicated by the “.” suffix in the instruction mnemonic.
The logical instructions do not update any bits in the XER register.
In the operand syntax for logical instructions, the
r
A operand specifies a
destination
register
rather than a source register.
r
S is used to specify one of the source registers.
AND and NAND Instructions
shows the PowerPC
AND and NAND
instructions. For each type of instruction
shown, the “Operation” column indicates the Boolean operation performed. The column
also shows, on an instruction-by-instruction basis, whether the CR0 field is updated.
Table 3-28:
Divide Instructions
Mnemonic
Name
Operation
Operand
Syntax
Divide-Word Instructions
r
D is loaded with the low-32 bits of the 64-bit quotient (
r
A)
÷
(
r
B).
divw
Divide Word
XER and CR0 are
not
updated.
r
D,
r
A,
r
B
divw.
Divide Word and Record
CR0 is updated to reflect the result.
divwo
Divide Word with Overflow Enabled
XER[OV,SO] are updated to reflect the result.
divwo.
Divide Word with Overflow Enabled
and Record
XER[OV,SO] and CR0 are updated to reflect the
result.
Divide-Word Unsigned Instructions
r
D is loaded with the low-32 bits of the 64-bit quotient (
r
A)
÷
(
r
B).
The contents of
r
A and
r
B are interpreted as unsigned integers.
divwu
Divide Word Unsigned
XER and CR0 are
not
updated.
r
D,
r
A,
r
B
divwu.
Divide Word Unsigned and Record
CR0 is updated to reflect the result.
divwuo
Divide Word Unsigned with Overflow
Enabled
XER[OV,SO] are updated to reflect the result.
divwuo.
Divide Word Unsigned with Overflow
Enabled and Record
XER[OV,SO] and CR0 are updated to reflect the
result.
Содержание Virtex-II Pro PPC405
Страница 1: ...R Volume 2 a PPC405 User Manual Virtex II Pro Platform FPGA Developer s Kit March 2002 Release...
Страница 14: ...322 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation Preface R...
Страница 252: ...560 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 260: ...568 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 562: ...870 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...