参数资料
| 型号： | T89C51AC2-RLTIM |
| 厂商： | Atmel |
| 文件页数： | 100/121页 |
| 文件大小： | 0K |
| 描述： | IC 8051 MCU FLASH 32K 44VQFP |
| 标准包装： | 160 |
| 系列： | 89C |
| 核心处理器： | 8051 |
| 芯体尺寸： | 8-位 |
| 速度： | 40MHz |
| 连通性： | UART/USART |
| 外围设备： | POR，PWM，WDT |
| 输入/输出数： | 34 |
| 程序存储器容量： | 32KB（32K x 8） |
| 程序存储器类型： | 闪存 |
| EEPROM 大小： | 2K x 8 |
| RAM 容量： | 1.25K x 8 |
| 电压 - 电源 (Vcc/Vdd)： | 3 V ~ 5.5 V |
| 数据转换器： | A/D 8x10b |
| 振荡器型： | 外部 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 44-LQFP |
| 包装： | 托盘 |
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8
A/T89C51AC2
4127H–8051–02/08
It is not obvious the last three instructions in this list are Read-Modify-Write instructions.
These instructions read the port (all 8 bits), modify the specifically addressed bit and
write the new byte back to the latch. These Read-Modify-Write instructions are directed
to the latch rather than the pin in order to avoid possible misinterpretation of voltage
(and therefore, logic) levels at the pin. For example, a Port bit used to drive the base of
an external bipolar transistor can not rise above the transistor’s base-emitter junction
voltage (a value lower than VIL). With a logic one written to the bit, attempts by the CPU
to read the Port at the pin are misinterpreted as logic zero. A read of the latch rather
than the pins returns the correct logic-one value.
Quasi-Bidirectional Port
Operation
Port 1, Port 2, Port 3 and Port 4 have fixed internal pull-ups and are referred to as
"quasi-bidirectional" Ports. When configured as an input, the pin impedance appears as
logic one and sources current in response to an external logic zero condition. Port 0 is a
"true bidirectional" pin. The pins float when configured as input. Resets write logic one to
all Port latches. If logical zero is subsequently written to a Port latch, it can be returned
to input conditions by a logical one written to the latch.
Note:
Port latch values change near the end of Read-Modify-Write instruction cycles. Output
buffers (and therefore the pin state) update early in the instruction after Read-Modify-
Write instruction cycle.
Logical zero-to-one transitions in Port 1, Port 2, Port 3 and Port 4 use an additional pull-
up (p1) to aid this logic transition (see Figure 4.). This increases switch speed. This
extra pull-up sources 100 times normal internal circuit current during 2 oscillator clock
periods. The internal pull-ups are field-effect transistors rather than linear resistors. Pull-
ups consist of three p-channel FET (pFET) devices. A pFET is on when the gate senses
logical zero and off when the gate senses logical one. pFET #1 is turned on for two
oscillator periods immediately after a zero-to-one transition in the Port latch. A logical
one at the Port pin turns on pFET #3 (a weak pull-up) through the inverter. This inverter
and pFET pair form a latch to drive logical one. pFET #2 is a very weak pull-up switched
on whenever the associated nFET is switched off. This is traditional CMOS switch con-
vention. Current strengths are 1/10 that of pFET #3.
Table 2. Read-Modify-Write Instructions
Instruction
Description
Example
ANL
logical AND
ANL P1, A
ORL
logical OR
ORL P2, A
XRL
logical EX-OR
XRL P3, A
JBC
jump if bit = 1 and clear bit
JBC P1.1, LABEL
CPL
complement bit
CPL P3.0
INC
increment
INC P2
DEC
decrement
DEC P2
DJNZ
decrement and jump if not zero
DJNZ P3, LABEL
MOV Px.y, C
move carry bit to bit y of Port x
MOV P1.5, C
CLR Px.y
clear bit y of Port x
CLR P2.4
SET Px.y
set bit y of Port x
SET P3.3
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相关代理商/技术参数 |
参数描述 |
|---|---|
| T89C51AC2-RLTI-M | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit MCU with 32K bytes Flash, 10 bits A/D and EEPROM |
| T89C51AC2-SLSC-M | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit MCU with 32K bytes Flash, 10 bits A/D and EEPROM |
| T89C51AC2-SLSE-M | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit MCU with 32K bytes Flash, 10 bits A/D and EEPROM |
| T89C51AC2-SLSIM | 功能描述:IC 8051 MCU FLASH 32K 44PLCC RoHS:否 类别:集成电路 (IC) >> 嵌入式 - 微控制器， 系列:89C 标准包装:9 系列:87C 核心处理器:8051 芯体尺寸:8-位 速度:40/20MHz 连通性:UART/USART 外围设备:POR，WDT 输入/输出数:32 程序存储器容量:32KB（32K x 8） 程序存储器类型:OTP EEPROM 大小:- RAM 容量:256 x 8 电压 - 电源 (Vcc/Vdd):4.5 V ~ 5.5 V 数据转换器:- 振荡器型:内部 工作温度:0°C ~ 70°C 封装/外壳:40-DIP（0.600"，15.24mm） 包装:管件 |
| T89C51AC2-SLSI-M | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit MCU with 32K bytes Flash, 10 bits A/D and EEPROM |
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