參數(shù)資料
型號: MC68HC705P6ACSD
廠商: MOTOROLA INC
元件分類: 微控制器/微處理器
英文描述: 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER
文件頁數(shù): 129/130頁
文件大小: 1541K
代理商: MC68HC705P6ACSD
Central Processor Unit (CPU) Core
Advance Information
MC68HC705P6A — Rev. 2.0
98
Central Processor Unit (CPU) Core
MOTOROLA
12.3.5 Condition Code Register
The CCR shown in Figure 12-1 is a 5-bit register in which four bits are
used to indicate the results of the instruction just executed. The fifth bit
is the interrupt mask. These bits can be individually tested by a program,
and specific actions can be taken as a result of their state. The condition
code register should be thought of as having three additional upper bits
that are always ones. Only the interrupt mask is affected by a reset of the
device. The following paragraphs explain the functions of the lower five
bits of the condition code register.
H — Half Carry Bit
When the half-carry bit is set, it means that a carry occurred between
bits 3 and 4 of the accumulator during the last ADD or ADC (add with
carry) operation. The half-carry bit is required for binary-coded
decimal (BCD) arithmetic operations.
I — Interrupt Mask Bit
When the interrupt mask is set, the internal and external interrupts are
disabled. Interrupts are enabled when the interrupt mask is cleared.
When an interrupt occurs, the interrupt mask is automatically set after
the CPU registers are saved on the stack, but before the interrupt
vector is fetched. If an interrupt request occurs while the interrupt
mask is set, the interrupt request is latched. Normally, the interrupt is
processed as soon as the interrupt mask is cleared.
A return from interrupt (RTI) instruction pulls the CPU registers from
the stack, restoring the interrupt mask to its state before the interrupt
was encountered. After any reset, the interrupt mask is set and can
only be cleared by the clear I bit (CLI), STOP, or WAIT instructions.
N — Negative Bit
The negative bit is set when the result of the last arithmetic operation,
logical operation, or data manipulation was negative. (Bit 7 of the
result was a logic one.)
The negative bit can also be used to check an often-tested flag by
assigning the flag to bit 7 of a register or memory location. Loading
the accumulator with the contents of that register or location then sets
or clears the negative bit according to the state of the flag.
相關(guān)PDF資料
PDF描述
MCHC705P6ACSDR2 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER
MC68HC705P6AMP 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDIP28
MC68HC705P6CDW 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDSO28
MC68HC705P6P 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDIP28
MC68HC705P6DW 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDSO28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68HC705P6ADW 制造商:Rochester Electronics LLC 功能描述:MCU, 176 BYTES RAM, A/D - Bulk
MC68HC705P6AMDW 功能描述:IC MCU 4.6K OTP 2.1MHZ 28-SOIC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:HC05 標(biāo)準(zhǔn)包裝:250 系列:56F8xxx 核心處理器:56800E 芯體尺寸:16-位 速度:60MHz 連通性:CAN,SCI,SPI 外圍設(shè)備:POR,PWM,溫度傳感器,WDT 輸入/輸出數(shù):21 程序存儲器容量:40KB(20K x 16) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:6K x 16 電壓 - 電源 (Vcc/Vdd):2.25 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 6x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 125°C 封裝/外殼:48-LQFP 包裝:托盤 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323
MC68HC705P6AMP 制造商:Rochester Electronics LLC 功能描述:- Bulk
MC68HC705P6CDW 制造商:Motorola Inc 功能描述:
MC68HC705P6CP 制造商:Freescale Semiconductor 功能描述: 制造商:Motorola Inc 功能描述: