参数资料
型号: AT90USB1287-MUR
厂商: Atmel
文件页数: 34/106页
文件大小: 0K
描述: MCU AVR 128K FLASH 16MHZ 64QFN
产品培训模块: MCU Product Line Introduction
megaAVR Introduction
标准包装: 1,000
系列: AVR® 90USB
核心处理器: AVR
芯体尺寸: 8-位
速度: 16MHz
连通性: EBI/EMI,I²C,SPI,UART/USART,USB,USB OTG
外围设备: 欠压检测/复位,POR,PWM,WDT
输入/输出数: 48
程序存储器容量: 128KB(128K x 8)
程序存储器类型: 闪存
EEPROM 大小: 4K x 8
RAM 容量: 8K x 8
电压 - 电源 (Vcc/Vdd): 2.7 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: 64-VFQFN 裸露焊盘
包装: 带卷 (TR)
33
7593L–AVR–09/12
AT90USB64/128
6.5.4
Pull-up and bus-keeper
The pull-ups on the AD7:0 ports may be activated if the corresponding Port register is written to
one. To reduce power consumption in sleep mode, it is recommended to disable the pull-ups by
writing the Port register to zero before entering sleep.
The XMEM interface also provides a bus-keeper on the AD7:0 lines. The bus-keeper can be dis-
abled and enabled in software as described in “XMCRB – External Memory Control Register B”
on page 36. When enabled, the bus-keeper will keep the previous value on the AD7:0 bus while
these lines are tri-stated by the XMEM interface.
6.5.5
Timing
External Memory devices have different timing requirements. To meet these requirements, the
XMEM interface provides four different wait-states as shown in Table 6-5 on page 36. It is impor-
tant to consider the timing specification of the External Memory device before selecting the wait-
state. The most important parameters are the access time for the external memory compared to
the setup requirement. The access time for the External Memory is defined to be the time from
receiving the chip select/address until the data of this address actually is driven on the bus. The
access time cannot exceed the time from the ALE pulse must be asserted low until data is stable
during a read sequence (see t
LLRL+ tRLRH - tDVRH in Tables 31-6 through Tables 31-13 on pages
399 - 401). The different wait-states are set up in software. As an additional feature, it is possible
to divide the external memory space in two sectors with individual wait-state settings. This
makes it possible to connect two different memory devices with different timing requirements to
the same XMEM interface. For XMEM interface timing details, please refer to Tables 31-6
Note that the XMEM interface is asynchronous and that the waveforms in the following figures
are related to the internal system clock. The skew between the internal and external clock
(XTAL1) is not guarantied (varies between devices temperature, and supply voltage). Conse-
quently, the XMEM interface is not suited for synchronous operation.
Figure 6-6.
External data memory cycles without wait-state (SRWn1=0 and SRWn0=0).
ALE
T1
T2
T3
Wr
ite
Re
a
d
WR
T4
A15:8
Address
Prev. addr.
DA7:0
Address
Data
Prev. data
XX
RD
DA7:0 (XMBK = 0)
Data
Prev. data
Address
Data
Prev. data
Address
DA7:0 (XMBK = 1)
System Clock (CLKCPU)
相关PDF资料
PDF描述
AT90USB1287-AUR MCU AVR 128K FLASH 16MHZ 64TQFP
VE-BTF-IX CONVERTER MOD DC/DC 72V 75W
VI-B3X-IX-F2 CONVERTER MOD DC/DC 5.2V 75W
VE-BTF-IW CONVERTER MOD DC/DC 72V 100W
VI-B3X-IW-F4 CONVERTER MOD DC/DC 5.2V 100W
相关代理商/技术参数
参数描述
AT90USB128X 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:USB DFU Bootloader
AT90USB162 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:8-bit Microcontroller with 8/16K Bytes of ISP Flash and USB Controller
AT90USB162-16AU 功能描述:8位微控制器 -MCU AVR USB 16K FLASH RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT90USB162-16AUR 功能描述:8位微控制器 -MCU 16K Flash RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT90USB162-16MU 功能描述:8位微控制器 -MCU AVR USB 16K FLASH RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT