参数资料
型号: AT83EB5114XXXTGRIL
厂商: ATMEL CORP
元件分类: 微控制器/微处理器
英文描述: Low-pin-count 8-bit microcontroller with A/D converter
中文描述: 8-BIT, MROM, 40 MHz, MICROCONTROLLER, PDSO20
封装: SO-20
文件页数: 24/95页
文件大小: 1126K
代理商: AT83EB5114XXXTGRIL
24
4311A–8051–01/05
Timers/Counters
Introduction
The AT8xEB5114 implements two general-purpose, 16-bit Timers/Counters. Although
they are identified as Timer 0, Timer 1, they can be independently configured each to
operate in a variety of modes as a Timer or as an event Counter. When operating as a
Timer, a Timer/Counter runs for a programmed length of time, then issues an interrupt
request. When operating as a Counter, a Timer/Counter counts negative transitions on
an external pin. After a preset number of counts, the Counter issues an interrupt
request.
The Timer registers and associated control registers are implemented as addressable
Special Function Registers (SFRs). Two of the SFRs provide programmable control of
the Timers as follows:
Timer/Counter mode control register (TMOD) and Timer/Counter control register
(TCON) control both Timer 0 and Timer 1.
The various operating modes of each Timer/Counter are described below.
Timer/Counter
Operations
A basic operation is Timer registers THx and TLx (x = 0, 1) connected in cascade to
form a 16-bit Timer. Setting the run control bit (TRx) in the TCON register (see
Figure 15) turns the Timer on by allowing the selected input to increment TLx. When
TLx overflows it increments THx and when THx overflows it sets the Timer overflow flag
(TFx) in the TCON register. Setting the TRx does not clear the THx and TLx Timer reg-
isters. Timer registers can be accessed to obtain the current count or to enter preset
values. They can be read at any time but the TRx bit must be cleared to preset their val-
ues, otherwise the behavior of the Timer/Counter is unpredictable.
The C/Tx# control bit selects Timer operation or Counter operation by selecting the
divided-down system clock or the external pin Tx as the source for the counted signal.
The TRx bit must be cleared when changing the operating mode, otherwise the behavior
of the Timer/Counter is unpredictable.
For Timer operation (C/Tx# = 0), the Timer register counts the divided-down system
clock. The Timer register is incremented once every peripheral cycle.
For Counter operation (C/Tx# = 1), the Timer register counts the negative transitions on
the external input pin Tx. The external input is sampled during every S5P2 state. The
Programmer’s Guide describes the notation for the states in a peripheral cycle. When
the sample is high in one cycle and low in the next one, the Counter is incremented. The
new count value appears in the register during the next S3P1 state after the transition
has been detected. Since it takes 12 states (24 oscillator periods in X1 mode) to recog-
nize a negative transition, the maximum count rate is 1/24 of the oscillator frequency in
X1 mode. There are no restrictions on the duty cycle of the external input signal, but to
ensure that a given level is sampled at least once before it changes, it should be held for
at least one full peripheral cycle.
Timer 0
Timer 0 functions as either a Timer or an event Counter in four operating modes.
Figure 7 to Figure 10 show the logic configuration of each mode.
Timer 0 is controlled by the four lower bits of the TMOD register (see Figure 16) and bits
0, 1, 4 and 5 of the TCON register (see Figure 15). The TMOD register selects the
method of Timer gating (GATE0), Timer or Counter operation (T/C0#) and the operating
mode (M10 and M00). The TCON register provides Timer 0 control functions: overflow
flag (TF0), run control bit (TR0), interrupt flag (IE0) and interrupt type control bit (IT0).
For normal Timer operation (GATE0= 0), setting TR0 allows TL0 to be incremented by
the selected input. Setting GATE0 and TR0 allows external pin INT0# to control Timer
相关PDF资料
PDF描述
AT89EB5114 Low-pin-count 8-bit microcontroller with A/D converter
AT89EB5114-TGSIL Low-pin-count 8-bit microcontroller with A/D converter
AT83EB5114 Low-pin-count 8-bit microcontroller with A/D converter
AT83R22OK CardMan Smart Key
AT83R22OK_06 CardMan Smart Key
相关代理商/技术参数
参数描述
AT83EB5114XXXTGRUL 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Low-pin-count 8-bit microcontroller with A/D converter
AT83EC5122 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
AT83EC5123 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
AT83EC5136-PLTUL 功能描述:IC MCU 8BIT 32KB FLASH 48MLF 制造商:microchip technology 系列:- 零件状态:Digi-Key 停止供應 核心处理器:80C52 核心尺寸:8-位 速度:48MHz 连接性:EBI/EMI,I2C,SPI,UART/USART,USB 外设:LED,POR,PWM,WDT I/O 数:34 程序存储容量:32KB(32K x 8) 程序存储器类型:闪存 EEPROM 容量:512 x 8 RAM 容量:1K x 8 电压 - 电源(Vcc/Vdd):2.7 V ~ 3.6 V 数据转换器:- 振荡器类型:内部 工作温度:-40°C ~ 85°C(TA) 基本零件编号:AT83EC5136 标准包装:260
AT83EC5136XXX-PNTUL 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit Microcontroller with Full Speed USB Device