參數(shù)資料
型號: AT43USB320A-AC
廠商: ATMEL CORP
元件分類: 微控制器/微處理器
英文描述: Full-speed USB Microcontroller with an Embedded Hub
中文描述: 8-BIT, 12 MHz, RISC MICROCONTROLLER, PQFP100
封裝: 14 X 14 MM, 1.40 MM HEIGHT, 0.50 MM PITCH, MS-026AED, LQFP-100
文件頁數(shù): 59/115頁
文件大?。?/td> 722K
代理商: AT43USB320A-AC
59
AT43USB320A
1443E–USB–4/04
Figure 19.
UART Transmitter
Data Reception
Figure 20 shows a block diagram of the UART Receiver.
The receiver front-end logic samples the signal on the RXD pin at a frequency 16 times the
baud rate. While the line is idle, one single sample of logical "0" will be interpreted as the fall-
ing edge of a start bit and the start bit detection sequence is initiated. Let sample 1 denote the
first zero-sample. Following the 1-to-0 transition, the receiver samples the RXD pin at samples
8, 9 and 10. If two or more of these three samples are found to be logical "1"s, the start bit is
rejected as a noise spike and the receiver starts looking for the next 1-to-0 transition.
If, however, a valid start bit is detected, sampling of the data bits following the start bit is per-
formed. These bits are also sampled at samples 8, 9 and 10. The logical value found in at
least two of the three samples is taken as the bit value. All bits are shifted into the Transmitter
Shift register as they are sampled. Sampling of an incoming character is shown in Figure 19.
When the stop bit enters the receiver, the majority of the three samples must be "1" to accept
the stop bit. If two or more samples are logical "0's, the Framing Error (FE) flag in the UART
Status Register (USR) is set. Before reading the UDR register, the user should always check
the FE bit to detect framing errors.
Whether or not a valid stop bit is detected at the end of a character reception cycle, the data is
transferred to UDR and the RXC flag in USR is set. UDR is in fact two physically separate reg-
相關(guān)PDF資料
PDF描述
AT43USB321 Full-speed USB Hub/Function Microcontroller
AT43USB325E-AC Multimedia USB Keyboard Controller with Embedded Hub
AT43USB325E-AU Multimedia USB Keyboard Controller with Embedded Hub
AT43USB326-AC Multimedia USB Keyboard Controller with Embedded Hub
AT43USB326-AU Multimedia USB Keyboard Controller with Embedded Hub
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AT43USB321 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Full-speed USB Hub/Function Microcontroller
AT43USB324AC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:KEYBOARD CONTROLLER
AT43USB324YC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:KEYBOARD CONTROLLER
AT43USB325 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Missed Watchdog Timer Reset
AT43USB325_05 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Multimedia USB Keyboard Controller with Embedded Hub