8XC251SA, SB, SP, SQ USER’S MANUAL
A-72
JNC rel
Function:
Jump if carry not set
Description:
If the CY flag is clear, branch to the address specified; otherwise proceed with the next
instruction. The branch destination is computed by adding the signed relative displacement
in the second instruction byte to the PC, after incrementing the PC twice to point to the next
instruction. The CY flag is not modified.
Flags:
Example:
The CY flag is set. The instruction sequence
JNC LABEL1
CPL CY
JNC LABEL2
clears the CY flag and causes program execution to continue at label LABEL2.
Binary Mode
Source Mode
Not Taken
Taken
Not Taken
Taken
Bytes:
2 2
2
2
States:
1
4
1
4
Hex Code in:
Binary Mode = [Encoding]
Source Mode = [Encoding]
Operation:
JNC
(PC)
←
(PC) + 2
IF (CY) = 0
THEN (PC)
←
(PC) + rel
JNE rel
Function:
Jump if not equal
Description:
If the Z flag is clear, branch to the address specified; otherwise proceed with the next
instruction. The branch destination is computed by adding the signed relative displacement
in the second instruction byte to the PC, after incrementing the PC twice.
Flags:
Example:
The instruction
JNE LABEL1
causes program execution to continue at LABEL1 if the Z flag is clear.
CY
AC
OV
N
Z
!
—
—
—
—
[Encoding]
0 1 0 1
0 0 0 0
rel. addr
CY
AC
OV
N
Z
—
—
—
—
!
Содержание 8XC251SA
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Страница 3: ...May 1996 8XC251SA 8XC251SB 8XC251SP 8XC251SQ Embedded Microcontroller User s Manual...
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Страница 19: ...1 Guide to This Manual...
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Страница 31: ...2 Architectural Overview...
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Страница 41: ...3 Address Spaces...
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Страница 63: ...4 Device Configuration...
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Страница 81: ...5 Programming...
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Страница 103: ...6 Interrupt System...
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Страница 121: ...7 Input Output Ports...
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Страница 133: ...8 Timer Counters and Watchdog Timer...
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Страница 153: ...9 Programmable Counter Array...
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Страница 171: ...10 Serial I O Port...
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Страница 187: ...11 Minimum Hardware Setup...
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Страница 197: ...12 Special Operating Modes...
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Страница 207: ...13 External Memory Interface...
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Страница 239: ...14 Programming and Verifying Nonvolatile Memory...
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Страница 250: ......
Страница 251: ...A Instruction Set Reference...
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Страница 391: ...B Signal Descriptions...
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Страница 401: ...C Registers...
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Страница 437: ...Glossary...
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Страница 447: ...Index...
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