參數(shù)資料
型號: AT90USB647-MU
廠商: Atmel
文件頁數(shù): 33/106頁
文件大小: 0K
描述: IC AVR MCU 64K 64QFN
產(chǎn)品培訓(xùn)模塊: megaAVR Introduction
標(biāo)準(zhǔn)包裝: 1,300
系列: AVR®
應(yīng)用: USB 微控制器
核心處理器: AVR
程序存儲器類型: 閃存(64 kB)
控制器系列: AT90 USB
RAM 容量: 4K x 8
接口: 2 線串行,SPI 串行,USART,USB
輸入/輸出數(shù): 48
電源電壓: 2.7 V ~ 5.5 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 64-VFQFN 裸露焊盤
包裝: 托盤
供應(yīng)商設(shè)備封裝: 64-VQFN(9x9)
配用: ATSTK600-TQFP64-ND - STK600 SOCKET/ADAPTER 64-TQFP
ATSTK525-ND - KIT STARTER FOR AT90USB
AT90USBKEY2-ND - KIT DEMO FOR AT90USB
其它名稱: AT90USB647-16MU
AT90USB647-16MU-ND
Q4939729A
32
7593L–AVR–09/12
AT90USB64/128
When the XMEM interface is enabled, the XMEM interface will override the setting in the data
direction registers that corresponds to the ports dedicated to the XMEM interface. For details
about the port override, see the alternate functions in section “I/O-ports” on page 71. The XMEM
interface will auto-detect whether an access is internal or external. If the access is external, the
XMEM interface will output address, data, and the control signals on the ports according to Fig-
ure 6-6 on page 33 (this figure shows the wave forms without wait-states). When ALE goes from
high-to-low, there is a valid address on AD7:0. ALE is low during a data transfer. When the
XMEM interface is enabled, also an internal access will cause activity on address, data and ALE
ports, but the RD and WR strobes will not toggle during internal access. When the External
Memory Interface is disabled, the normal pin and data direction settings are used. Note that
when the XMEM interface is disabled, the address space above the internal SRAM boundary is
not mapped into the internal SRAM. Figure 6-5 illustrates how to connect an external SRAM to
the AVR using an octal latch (typically “74 × 573” or equivalent) which is transparent when G is
high.
6.5.3
Address latch requirements
Due to the high-speed operation of the XRAM interface, the address latch must be selected with
care for system frequencies above 8MHz @ 4V and 4MHz @ 2.7V. When operating at condi-
tions above these frequencies, the typical old style 74HC series latch becomes inadequate. The
External Memory Interface is designed in compliance to the 74AHC series latch. However, most
latches can be used as long they comply with the main timing parameters. The main parameters
for the address latch are:
D to Q propagation delay (t
PD)
Data setup time before G low (t
SU)
Data (address) hold time after G low (
TH)
The External Memory Interface is designed to guaranty minimum address hold time after G is
asserted low of t
h = 5ns. Refer to tLAXX_LD/tLLAXX_ST in “External data memory timing” Tables 31-7
through Tables 31-13 on pages 399 - 401. The D-to-Q propagation delay (t
PD) must be taken
into consideration when calculating the access time requirement of the external component. The
data setup time before G low (t
SU) must not exceed address valid to ALE low (tAVLLC) minus PCB
wiring delay (dependent on the capacitive load).
Figure 6-5.
External SRAM connected to the AVR.
D[7:0]
A[7:0]
A[15:8]
RD
WR
SRAM
DQ
G
AD7:0
ALE
A15:8
RD
WR
AVR
相關(guān)PDF資料
PDF描述
395-020-527-801 CARD EDGE 20POS DL .100X.200 BLK
395-020-527-204 CARD EDGE 20POS DL .100X.200 BLK
FT24C02A-UNR-T IC EEPROM 2KBIT 1MHZ 8DFN
AYF332365 CONN FPC 23POS SMD Y3BW
AT90USB647-AU IC AVR MCU 64K 64TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AT90USB647-MUR 功能描述:8位微控制器 -MCU USB 64K FLASH 16 MHz RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT90USB64X 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:USB DFU Bootloader
AT90USB82 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 8/16K Bytes of ISP Flash and USB Controller
AT90USB82_0811 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:8-bit Microcontroller with 8/16K Bytes of ISP Flash and USB Controller
AT90USB82-16MU 功能描述:8位微控制器 -MCU AVR USB 8K FLASH RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT