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Chapter 3
CPU Functions
User’s Manual U16580EE3V1UD00
3.2.3 Floating point arithmetic unit register set
The floating point arithmetic unit is provided with one flag register and one control register.
(1)
Floating point arithmetic control register (ECT)
This register is used for controlling the setting conditions of the TR flag:
TR is a logical OR between all the invalid operations the FPU can detect and each bit of ECT is a
mask bit for each condition.
Figure 3-10:
Floating Point Arithmetic Control Register (ECT)
Table 3-4:
Floating Point Arithmetic Unit Registers
Name
Usage
Operation
ECT
Control register
Sets the operation of the EFG register
EFG
Flag register
Holds the status of the FPU
31
13 12 11 10 9 8 7 6 5
4
3 2 1 0
After reset
00000000H
ECT
RFU
IT ZT VT UT PT 0
0
0
0
0
0
0 0
Bit position
Bit name
Description
31 to 13
RFU
Reserved field. Fixed to 0.
12
IT
Enables invalid operation detection in the TR value calculation
0: IV is set when an invalid operation is detected
1: IV and TR are set when an invalid operation is detected
11
ZT
Enables zero divide operation detection in the TR value calculation
0: ZD is set when a zero divide operation is detected
1: ZD and TR are set when a zero divide operation is detected
10
VT
Enables overflow detection in the TR value calculation
0: VF is set when an overflow is detected
1: VF and TR are set when an overflow is detected
9
UT
Enables underflow detection in the TR value calculation
0: UD is set when an underflow is detected
1: UD and TR are set when an underflow is detected
8
PT
Enables accuracy fail detection in the TR value calculation
0: PR is set when an accuracy fail is detected
1: PR and TR are set when an accuracy fail is detected
7 to 0
0
Reserved field. Fixed to 0.
Summary of Contents for MuPD70F3187
Page 6: ...6 Preface User s Manual U16580EE3V1UD00 ...
Page 16: ...16 User s Manual U16580EE3V1UD00 ...
Page 28: ...28 User s Manual U16580EE3V1UD00 ...
Page 32: ...32 User s Manual U16580EE3V1UD00 ...
Page 84: ...84 Chapter 2 Pin Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 144: ...144 Chapter 3 CPU Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 312: ...312 Chapter 9 16 Bit Timer Event Counter P User s Manual U16580EE3V1UD00 MEMO ...
Page 534: ...534 Chapter 11 16 bit Timer Event Counter T User s Manual U16580EE3V1UD00 ...
Page 969: ...969 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 MEMO ...
Page 970: ...970 Chapter 20 Port Functions User s Manual U16580EE3V1UD00 ...
Page 976: ...976 Chapter 22 Internal RAM Parity Check Function User s Manual U16580EE3V1UD00 MEMO ...
Page 984: ...984 Chapter 23 On Chip Debug Function OCD User s Manual U16580EE3V1UD00 MEMO ...
Page 1006: ...1006 Chapter 24 Flash Memory User s Manual U16580EE3V1UD00 MEMO ...
Page 1036: ...1036 Chapter 27 Recommended Soldering Conditions User s Manual U16580EE3V1UD00 MEMO ...
Page 1046: ...1046 Appendix A Index User s Manual U16580EE3V1UD00 MEMO ...
Page 1052: ...1052 User s Manual U16580EE3V1UD00 ...
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