参数资料
型号: MQ80C52XXX-36/883
厂商: ATMEL CORP
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 36 MHz, MICROCONTROLLER, CQFP44
封装: CERAMIC, QFP-44
文件页数: 2/152页
文件大小: 2528K
代理商: MQ80C52XXX-36/883
10
ATmega8535(L)
2502K–AVR–10/06
Status Register
The Status Register contains information about the result of the most recently executed
arithmetic instruction. This information can be used for altering program flow in order to
perform conditional operations. Note that the Status Register is updated after all ALU
operations, as specified in the Instruction Set Reference. This will, in many cases,
remove the need for using the dedicated compare instructions, resulting in faster and
more compact code.
The Status Register is not automatically stored when entering an interrupt routine and
restored when returning from an interrupt. This must be handled by software.
The AVR Status Register – SREG – is defined as:
Bit 7 – I: Global Interrupt Enable
The Global Interrupt Enable bit must be set for the interrupts to be enabled. The individ-
ual interrupt enable control is then performed in separate control registers. If the Global
Interrupt Enable Register is cleared, none of the interrupts are enabled independent of
the individual interrupt enable settings. The I-bit is cleared by hardware after an interrupt
has occurred, and is set by the RETI instruction to enable subsequent interrupts. The I-
bit can also be set and cleared by the application with the SEI and CLI instructions, as
described in the instruction set reference.
Bit 6 – T: Bit Copy Storage
The Bit Copy instructions BLD (Bit LoaD) and BST (Bit STore) use the T-bit as source or
destination for the operated bit. A bit from a register in the Register file can be copied
into T by the BST instruction, and a bit in T can be copied into a bit in a register in the
Register File by the BLD instruction.
Bit 5 – H: Half Carry Flag
The Half Carry Flag H indicates a Half Carry in some arithmetic operations. Half carry is
useful in BCD arithmetic. See the “Instruction Set Description” for detailed information.
Bit 4 – S: Sign Bit, S = N
V
The S-bit is always an exclusive or between the Negative Flag N and the Two’s Comple-
ment Overflow Flag V. See the “Instruction Set Description” for detailed information.
Bit 3 – V: Two’s Complement Overflow Flag
The Two’s Complement Overflow Flag V supports two’s complement arithmetics. See
the “Instruction Set Description” for detailed information.
Bit 2 – N: Negative Flag
The Negative Flag N indicates a negative result in an arithmetic or logic operation. See
the “Instruction Set Description” for detailed information.
Bit 1 – Z: Zero Flag
The Zero Flag Z indicates a zero result in an arithmetic or logic operation. See the
“Instruction Set Description” for detailed information.
Bit 0 – C: Carry Flag
The Carry Flag C indicates a carry in an arithmetic or logic operation. See the “Instruc-
tion Set Description” for detailed information.
Bit
765432
10
I
T
H
S
V
N
Z
C
SREG
Read/Write
R/W
Initial Value
000000
00
相关PDF资料
PDF描述
S80C32-L16D 8-BIT, 16 MHz, MICROCONTROLLER, PQCC44
MP80C51C-36D 8-BIT, MROM, 36 MHz, MICROCONTROLLER, PDIP40
MR80C52EXXX-16SHXXX:R 8-BIT, MROM, 16 MHz, MICROCONTROLLER, CQCC44
MD83C154DCXXX-25P883D 8-BIT, MROM, 25 MHz, MICROCONTROLLER, CDIP40
S80C32E-20R 8-BIT, 20 MHz, MICROCONTROLLER, PQCC44
相关代理商/技术参数
参数描述
MQ82370-20 制造商:Rochester Electronics LLC 功能描述:- Bulk
MQ8238020 制造商:Intel 功能描述:CONTROLLER: OTHER
MQ82380-20 制造商:Rochester Electronics LLC 功能描述:- Bulk
MQ82380-20/R 制造商:Rochester Electronics LLC 功能描述:
MQ82592 制造商:Rochester Electronics LLC 功能描述:- Bulk