参数资料
型号: ATMEGA1284-PU
厂商: Atmel
文件页数: 37/160页
文件大小: 0K
描述: IC MCU AVR 128K FLASH 40PDIP
产品培训模块: MCU Product Line Introduction
megaAVR Introduction
标准包装: 10
系列: AVR® ATmega
核心处理器: AVR
芯体尺寸: 8-位
速度: 20MHz
连通性: I²C,SPI,UART/USART
外围设备: 欠压检测/复位,POR,PWM,WDT
输入/输出数: 32
程序存储器容量: 128KB(64K x 16)
程序存储器类型: 闪存
EEPROM 大小: 4K x 8
RAM 容量: 16K x 8
电压 - 电源 (Vcc/Vdd): 1.8 V ~ 5.5 V
数据转换器: A/D 8x10b
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
配用: ATSTK600-RC05-ND - STK600 ROUTING CARD AVR
131
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
Using the ICRn Register for defining TOP works well when using fixed TOP values. By using
ICRn, the OCRnA Register is free to be used for generating a PWM output on OCnA. However,
if the base PWM frequency is actively changed by changing the TOP value, using the OCRnA as
TOP is clearly a better choice due to its double buffer feature.
In phase and frequency correct PWM mode, the compare units allow generation of PWM wave-
forms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM and
an inverted PWM output can be generated by setting the COMnx1:0 to three (See Table 16-4 on
page 134). The actual OCnx value will only be visible on the port pin if the data direction for the
port pin is set as output (DDR_OCnx). The PWM waveform is generated by setting (or clearing)
the OCnx Register at the compare match between OCRnx and TCNTn when the counter incre-
ments, and clearing (or setting) the OCnx Register at compare match between OCRnx and
TCNTn when the counter decrements. The PWM frequency for the output when using phase
and frequency correct PWM can be calculated by the following equation:
The N variable represents the prescaler divider (1, 8, 64, 256, or 1024).
The extreme values for the OCRnx Register represents special cases when generating a PWM
waveform output in the phase correct PWM mode. If the OCRnx is set equal to BOTTOM the
output will be continuously low and if set equal to TOP the output will be set to high for non-
inverted PWM mode. For inverted PWM the output will have the opposite logic values. If OCR1A
is used to define the TOP value (WGM13:0 = 9) and COM1A1:0 = 1, the OC1A output will toggle
with a 50% duty cycle.
16.11 Timer/Counter Timing diagrams
The Timer/Counter is a synchronous design and the timer clock (clk
Tn) is therefore shown as a
clock enable signal in the following figures. The figures include information on when Interrupt
Flags are set, and when the OCRnx Register is updated with the OCRnx buffer value (only for
modes utilizing double buffering). Figure 16-10 shows a timing diagram for the setting of OCFnx.
Figure 16-10. Timer/Counter Timing diagram, setting of OCFnx, no prescaling.
Figure 16-11 shows the same timing data, but with the prescaler enabled.
f
OCnxPFCPWM
fclk_I/O
2 NTOP
----------------------------
=
clk
Tn
(clk
I/O/1)
OCFnx
clk
I/O
OCRnx
TCNTn
OCRnx Value
OCRnx - 1
OCRnx
OCRnx + 1
OCRnx + 2
相关PDF资料
PDF描述
VE-B2M-IY-F3 CONVERTER MOD DC/DC 10V 50W
VE-B2M-IY-F2 CONVERTER MOD DC/DC 10V 50W
ATMEGA3250V-8AU IC AVR MCU 32K 8MHZ 100TQFP
ATMEGA3250-16AU IC AVR MCU 32K 16MHZ 100TQFP
VE-B2L-IY-F3 CONVERTER MOD DC/DC 28V 50W
相关代理商/技术参数
参数描述
ATMEGA1284P-XPLD 功能描述:开发板和工具包 - AVR MEGA-1284P Xplained Evaluation kit RoHS:否 制造商:Arduino 产品:Evaluation Boards 工具用于评估:ATMega32U4 核心:AVR 接口类型:I2C, UART, USB 工作电源电压:6 V to 20 V
ATMEGA1284RFR2-ZF 制造商:Atmel Corporation 功能描述:2.4GHZ 128K SOC 48PIN IND 125C TRAY - Trays 制造商:Atmel Corporation 功能描述:IC MCU 8BIT 128KB FLASH 48VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 128K SOC 48pin Ind 125C Tray
ATMEGA1284RFR2-ZFR 制造商:Atmel Corporation 功能描述:2.4GHZ 128K SOC 48 PIN IND125C T&R - Tape and Reel 制造商:Atmel Corporation 功能描述:IC MCU 8BIT 128KB FLASH 48VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 128K SOC 48 pin Ind125C T&R
ATMEGA1284RFR2-ZU 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 48PIN TRAY - Trays 制造商:Atmel Corporation 功能描述:IC MCU 8BIT 128KB FLASH 48VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 48pin Tray
ATMEGA1284RFR2-ZUR 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 48PIN T&R - Tape and Reel 制造商:Atmel Corporation 功能描述:IC MCU 8BIT 128KB FLASH 48VQFN 制造商:Atmel Corporation 功能描述:2.4GHZ 802.15.4 128K SOC 48pin T&R