参数资料
型号: AT89LV55-12PI
厂商: Atmel
文件页数: 6/32页
文件大小: 0K
描述: IC 8051 MCU FLASH 20K 40DIP
标准包装: 10
系列: 89LV
核心处理器: 8051
芯体尺寸: 8-位
速度: 12MHz
连通性: UART/USART
输入/输出数: 32
程序存储器容量: 20KB(20K x 8)
程序存储器类型: 闪存
RAM 容量: 256 x 8
电压 - 电源 (Vcc/Vdd): 2.7 V ~ 6 V
振荡器型: 内部
工作温度: -40°C ~ 85°C
封装/外壳: 40-DIP(0.600",15.24mm)
包装: 管件
14
0811E–MICRO–9/08
AT89LV55
12. Interrupts
The AT89LV55 has a total of six interrupt vectors: two external interrupts (INT0 and INT1), three
timer interrupts (Timers 0, 1, and 2), and the serial port interrupt. These interrupts are all shown
Each of these interrupt sources can be individually enabled or disabled by setting or clearing a
bit in Special Function Register IE. IE also contains a global disable bit, EA, which disables all
interrupts at once.
Note that Table 12-1 shows that bit position IE.6 is unimplemented. In the AT89C51 and
AT89LV51, bit position IE.5 is also unimplemented. User software should not write 1s to these
bit positions, since they may be used in future AT89 products.
Timer 2 interrupt is generated by the logical OR of bits TF2 and EXF2 in register T2CON. Nei-
ther of these flags is cleared by hardware when the service routine is vectored to. In fact, the
service routine may have to determine whether it was TF2 or EXF2 that generated the interrupt,
and that bit will have to be cleared in software.
The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers
overflow. The values are then polled by the circuitry in the next cycle. However, the Timer 2 flag,
TF2, is set at S2P2 and is polled in the same cycle in which the timer overflows. For further infor-
mation, see the Microcontroller Data Book, section titled “Interrupts.”
Table 12-1.
Interrupt Enable (IE) Register
(MSB)
(LSB)
EA
ET2
ES
ET1
EX1
ET0
EX0
Enable Bit = 1 enables the interrupt.
Enable Bit = 0 disables the interrupt.
Symbol
Position
Function
EA
IE.7
Disables all interrupts. If EA = 0, no interrupt is acknowledged. If EA = 1, each
interrupt source is individually enabled or disabled by setting or clearing its
enable bit.
IE.6
Reserved.
ET2
IE.5
Timer 2 interrupt enable bit.
ES
IE.4
Serial Port interrupt enable bit.
ET1
IE.3
Timer 1 interrupt enable bit.
EX1
IE.2
External interrupt 1 enable bit.
ET0
IE.1
Timer 0 interrupt enable bit.
EX0
IE.0
External interrupt 0 enable bit.
User software should never write 1s to unimplemented bits, because they may be used in future AT89 products.
相关PDF资料
PDF描述
AT89S4051-24SU IC 8051 MCU FLASH 4K LF 20SOIC
AT89S51-24AU IC MCU 4K FLASH 24MHZ 44-TQFP
AT89S52-24AU IC MCU 8K FLASH 24MHZ 44-TQFP
AT89S53-24JU MICRO CONTROLLER 44PLCC
AT89S8252-24PI MCU W/SPI 8KB FLSH 2K EEP 40-DIP
相关代理商/技术参数
参数描述
AT89OCD-01 功能描述:仿真器/模拟器 Emulator to load/ debug AtmelAT8xC51 RoHS:否 制造商:Blackhawk 产品:System Trace Emulators 工具用于评估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2
AT89RFD-01 功能描述:音频 IC 开发工具 MP3 Reference Design Chejudo RoHS:否 制造商:Texas Instruments 产品:Evaluation Kits 类型:Audio Amplifiers 工具用于评估:TAS5614L 工作电源电压:12 V to 38 V
AT89RFD-02 功能描述:界面开发工具 AT83C22OK/AT83C23OK Reference Design RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V
AT89RFD-05 功能描述:界面开发工具 SCR Reference Design RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V
AT89RFD-06 功能描述:界面开发工具 AT83C25OK Ref Design RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V