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Section 3 Floating-Point Unit (FPU)................................................................. 101
3.1
Features............................................................................................................................. 101
3.2
Data Formats..................................................................................................................... 102
3.2.1
Floating-Point Format....................................................................................... 102
3.2.2
Non-Numbers (NaN) ........................................................................................ 105
3.2.3
Denormalized Numbers .................................................................................... 106
3.3
Register Descriptions........................................................................................................ 107
3.3.1
Floating-Point Registers ................................................................................... 107
3.3.2
Floating-Point Status/Control Register (FPSCR) ............................................. 108
3.3.3
Floating-Point Communication Register (FPUL) ............................................. 110
3.4
Rounding .......................................................................................................................... 111
3.5
FPU Exceptions ................................................................................................................ 112
3.5.1
FPU Exception Sources .................................................................................... 112
3.5.2
FPU Exception Handling .................................................................................. 112
Section 4 Boot Mode ......................................................................................... 115
4.1
Features............................................................................................................................. 115
4.2
Boot Mode and Pin Function Setting................................................................................ 116
4.3
Operation .......................................................................................................................... 117
4.3.1
Boot Modes 0 and 1 .......................................................................................... 117
4.3.2
Boot Mode 2 ..................................................................................................... 117
4.3.3
Boot Mode 3 ..................................................................................................... 119
4.3.4
Boot Mode 4 ..................................................................................................... 121
4.3.5
Boot Mode 5 ..................................................................................................... 122
4.4
Notes................................................................................................................................. 124
4.4.1
Boot Related Pins ............................................................................................. 124
Section 5 Clock Pulse Generator....................................................................... 125
5.1
Features............................................................................................................................. 125
5.2
Input/Output Pins.............................................................................................................. 129
5.3
Clock Mode ......................................................................................................................130
5.4
Register Descriptions........................................................................................................ 132
5.4.1
Frequency Control Register (FRQCR) ............................................................. 132
5.5
Changing the Frequency ................................................................................................... 135
5.5.1
Changing the Division Ratio............................................................................. 135
5.6
Usage of the Clock Pins.................................................................................................... 136
5.6.1
In the Case of Inputting an External Clock....................................................... 136
5.6.2
In the Case of Using a Crystal Resonator ......................................................... 137
5.6.3
In the Case of Not Using the Clock Pin ............................................................ 137
5.7
Oscillation Stabilizing Time ............................................................................................. 138