
CL-PS7500FE
System-on-a-Chip for Internet Appliance
June 1997
9
ADVANCE DATA BOOK v2.0
TABLE OF CONTENTS
17. FPA COPROCESSOR MACROCELL ................................................................................156
17.1
FPA Functional Blocks....................................................................................................................157
17.1.1
Coprocessor Interface ....................................................................................................157
17.1.2
Instruction Issuer ............................................................................................................157
17.1.3
The Load-Store Unit .......................................................................................................157
17.1.4
The Register Bank..........................................................................................................157
17.1.5
The Arithmetic Unit.........................................................................................................158
18. FLOATING-POINT COPROCESSOR PROGRAMMER’S MODEL...................................160
18.1
Overview.........................................................................................................................................160
18.1.1
Floating-Point Status Register........................................................................................160
18.1.2
Floating-Point Control Register.......................................................................................160
18.2
Floating-Point Operation.................................................................................................................160
18.3
ARM Integer and Floating-Point Number Formats .........................................................................161
18.3.1
Integer.............................................................................................................................161
18.3.2
IEEE Single Precision (S)...............................................................................................161
18.3.3
IEEE Double Precision (D) .............................................................................................161
18.3.4
IEEE Extended Double Precision (E) .............................................................................162
18.3.5
Packed Decimal (P)........................................................................................................163
18.3.6
Expanded Packed Decimal (EP).....................................................................................163
18.4
The Floating-Point Status Register (FPSR)....................................................................................164
18.4.1
System ID Byte...............................................................................................................164
18.4.2
Exception Trap Enable Byte............................................................................................165
18.4.3
System Control Byte.......................................................................................................165
18.4.4
Cumulative Exception Flags Byte...................................................................................166
18.5
The Floating-Point Control Register (FPCR)..................................................................................168
19. FLOATING-POINT INSTRUCTION SET.............................................................................170
19.1
Coprocessor Data Transfer.............................................................................................................170
19.1.1
LDF/STF — Load and Store Floating.............................................................................170
19.1.2
Assembler Syntax...........................................................................................................171
19.1.3
Load and Store Multiple Floating Instructions ................................................................172
19.1.4
Assembler Syntax — Form 1..........................................................................................173
19.1.5
Assembler Syntax — Form 2..........................................................................................174
19.2
Coprocessor Data Operations........................................................................................................174
19.2.1
Dyadic Operations ..........................................................................................................174
19.2.2
Monadic Operations........................................................................................................175
19.2.3
Library Calls....................................................................................................................175
19.2.4
Backwards Compatibility.................................................................................................175
19.3
Coprocessor Register Transfer.......................................................................................................178
19.3.1
Compare Operations ......................................................................................................179
19.4
FPA Instruction Set........................................................................................................................180
19.4.1
Infinities and NaNs..........................................................................................................180
19.4.2
Exceptional Conditions...................................................................................................180
19.5
Floating-point Support Code ..........................................................................................................182
19.5.1
IEEE Standard Conformance .........................................................................................182
19.6
Instruction Cycle Timing .................................................................................................................183
19.6.1
Instruction Classification.................................................................................................184
19.6.2
Performance Tuning........................................................................................................185