37
CHAPTER 5 CPU
5.1.3
Condition Code Register (CCR)
The condition code register (CCR) in the lower eight bits of the program status (PS)
register consists of the bits (H, N, Z, V, and C) containing information about the
arithmetic result or transfer data and the bits (I, IL1, and IL0) used to control the
acceptance of interrupt requests.
■
Configuration of Condition Code Register (CCR)
Figure 5.1-5 Configuration of Condition Code Register
The condition code register is a part of the program status (PS) register and therefore cannot be accessed
independently.
■
Bits Result Information Bits
●
Half carry flag (H)
This flag is set to "1" when a carry from bit 3 to bit 4 or a borrow from bit 4 to bit 3 occurs as the result of
an operation. Otherwise, the flag is set to "0". Do not use this flag for any operation other than addition and
subtraction as the flag is intended for decimal-adjusted instructions.
●
Negative flag (N)
This flag is set to "1" when the value of the most significant bit is "1" as the result of an operation and set to
"0" if the value is "0".
●
Zero flag (Z)
This flag is set to "1" when the result of an operation is "0" and set to "0" otherwise.
●
Overflow flag (V)
This flag indicates whether an operation has resulted in an overflow, assuming the operand used for the
operation as an integer represented by a two's complement. The flag is set to "1" when an overflow occurs
and set to "0" otherwise.
RP
DP
CCR
bit15 bit14 bit13 bit12 bit11 bit10 bit9 bit8 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
PS
R4
R3
R2
R1
R0
DP2 DP1 DP0
H
I
IL1
IL0
N
Z
V
C
00110000
B
Half carry flag
Interrupt enable flag
Interrupt level bits
Negative flag
Zero flag
Overflow flag
Carry flag
CCR Initial
value
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......