參數(shù)資料
型號(hào): M37643M8-XXXHP
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 12 MHz, MICROCONTROLLER, PQFP80
封裝: 12 X 12 MM, 0.50 MM PITCH, PLASTIC, LQFP-80
文件頁數(shù): 24/123頁
文件大小: 1292K
代理商: M37643M8-XXXHP
7643 Group
Rev.2.00
Aug 28, 2006
page 10 of 119
REJ03B0054-0200
[Processor status register (PS)]
The processor status register is an 8-bit register consisting of 5 flags
which indicate the status of the processor after an arithmetic opera-
tion and 3 flags which decide MCU operation. Branch operations can
be performed by testing the Carry (C) flag , Zero (Z) flag, Overflow
(V) flag, or the Negative (N) flag. In decimal mode, the Z, V, N flags
are not valid.
Bit 0: Carry flag (C)
The C flag contains a carry or borrow generated by the arithmetic
logic unit (ALU) immediately after an arithmetic operation. It can
also be changed by a shift or rotate instruction.
Bit 1: Zero flag (Z)
The Z flag is set if the result of an immediate arithmetic operation
or a data transfer is “0”, and cleared if the result is anything other
than “0”.
Bit 2: Interrupt disable flag (I)
The I flag disables all interrupts except for the interrupt
generated by the BRK instruction.
Interrupts are disabled when the I flag is “1”.
Bit 3: Decimal mode flag (D)
The D flag determines whether additions and subtractions are
executed in binary or decimal. Binary arithmetic is executed when
this flag is “0”; decimal arithmetic is executed when it is “1”.
Decimal correction is automatic in decimal mode. Only the ADC
and SBC instructions can execute decimal arithmetic.
Bit 4: Break flag (B)
The B flag is used to indicate that the current interrupt was
generated by the BRK instruction. The BRK flag in the processor
status register is always “0”. When the BRK instruction is used to
generate an interrupt, the processor status register is pushed
onto the stack with the break flag set to “1”.
Bit 5: Index X mode flag (T)
When the T flag is “0”, arithmetic operations are performed
between accumulator and memory. When the T flag is “1”, direct
arithmetic operations and direct data transfers are enabled
between memory locations.
Bit 6: Overflow flag (V)
The V flag is used during the addition or subtraction of one byte
of signed data. It is set if the result exceeds +127 to -128. When
the BIT instruction is executed, bit 6 of the memory location
operated on by the BIT instruction is stored in the overflow flag.
Bit 7: Negative flag (N)
The N flag is set if the result of an arithmetic operation or data
transfer is negative. When the BIT instruction is executed, bit 7 of
the memory location operated on by the BIT instruction is stored
in the negative flag.
Table 5 Set and clear instructions of each bit of processor status register
Set instruction
Clear instruction
C flag
SEC
CLC
Z flag
I flag
SEI
CLI
D flag
SED
CLD
B flag
T flag
SET
CLT
V flag
CLV
N flag
相關(guān)PDF資料
PDF描述
M37643F8HP 8-BIT, FLASH, 12 MHz, MICROCONTROLLER, PQFP80
M37700E2AFS 16-BIT, UVPROM, 16 MHz, MICROCONTROLLER, CQCC80
M37700E2AXXXFP 16-BIT, OTPROM, 16 MHz, MICROCONTROLLER, PQFP80
M37701E2-XXXSP 16-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDIP64
M37702E4EXXXFP 16-BIT, OTPROM, 16 MHz, MICROCONTROLLER, PQFP80
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
M3764A-12 制造商:OK International 功能描述:
M3765 制造商:未知廠家 制造商全稱:未知廠家 功能描述:HORN/SIREN WITH SOFT CHIRP 6 ALARM SOUNDS
M3766 制造商:未知廠家 制造商全稱:未知廠家 功能描述:HORN/SIREN WITH SOFT CHIRP 6 ALARM SOUNDS
M37702E2LGP 制造商:Mitsubishi Electric 功能描述:
M37702E4BFS 制造商:Renesas Electronics Corporation 功能描述:EPROM MCU/8BIT CMOS EMULATION CHIP - Bulk