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CHAPTER 3 CPU
3.7.4
Condition Code Register (PS: CCR)
The condition code register (CCR) is an 8-bit register that consists of the bits that
indicate the results of an arithmetic operation and the contents of transfer data and bits
that control interrupt request acceptance.
■
Condition Code Register (CCR) Configuration
Figure 3.7-9 shows the configuration of the CCR register. Refer to the programming manual for details
about the status of the condition code register (CCR) during instruction execution.
Figure 3.7-9 Condition Code Register (CCR) Configuration
●
Interrupt enable flag (I)
In response to all interrupt requests other than software interrupts, when the I flag is "1", interrupts are
enabled. When the I flag is "0", interrupts are disabled. Cleared by a reset.
●
Stack flag (S)
This flag indicates the pointer used for a stack operation.
When the S flag is "0", the user stack pointer (USP) is valid. When the S flag is "1", the system stack
pointer (SSP) is valid. Set when an interrupt is accepted or when a reset occurs.
●
Sticky bit flag (T)
Set to "1" when the data shifted out by the carry contains at least one 1 during execution of a logical right
shift instruction or arithmetic right shift instruction. Otherwise, set to "0". Also set to "0" when the shift
amount is zero.
●
Negative flag (N)
Set to "1" when the MSB is ""1 as the result of an arithmetic calculation. Cleared to "0 "when the MSB is
"0".
●
Zero flag (Z)
Set to "1" when the result of an arithmetic calculation is all zeros. Otherwise, set to "0".
–
I
S
T
N
Z
V
C
7
6
5
4
3
2
1
0
: CCR
Default value
⇒
–
0
1
x
x
x
x
x
x : Undefined
- : Not used
Interrupt enable flag
Stack flag
Sticky flag
Negative flag
Zero flag
Overflow flag
Carry flag
bit
Содержание MB90460 Series
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Страница 41: ...22 CHAPTER 1 OVERVIEW ...
Страница 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Страница 83: ...64 CHAPTER 3 CPU ...
Страница 95: ...76 CHAPTER 4 RESET ...
Страница 107: ...88 CHAPTER 5 CLOCK ...
Страница 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Страница 175: ...156 CHAPTER 7 INTERRUPT ...
Страница 181: ...162 CHAPTER 8 MODE SETTING ...
Страница 223: ...204 CHAPTER 9 I O PORT ...
Страница 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Страница 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Страница 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Страница 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Страница 485: ...466 CHAPTER 16 PWC Timer ...
Страница 531: ...512 CHAPTER 17 UART ...
Страница 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Страница 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Страница 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Страница 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Страница 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
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Страница 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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