181
7810C–AVR–10/12
Atmel ATmega328P [Preliminary]
19.7.5
Parity Checker
The Parity Checker is active when the high USART Parity mode (UPMn1) bit is set. Type of Par-
ity Check to be performed (odd or even) is selected by the UPMn0 bit. When enabled, the Parity
Checker calculates the parity of the data bits in incoming frames and compares the result with
the parity bit from the serial frame. The result of the check is stored in the receive buffer together
with the received data and stop bits. The Parity Error (UPEn) Flag can then be read by software
to check if the frame had a Parity Error.
The UPEn bit is set if the next character that can be read from the receive buffer had a Parity
Error when received and the Parity Checking was enabled at that point (UPMn1 = 1). This bit is
valid until the receive buffer (UDRn) is read.
19.7.6
Disabling the Receiver
In contrast to the Transmitter, disabling of the Receiver will be immediate. Data from ongoing
receptions will therefore be lost. When disabled (i.e., the RXENn is set to zero) the Receiver will
no longer override the normal function of the RxDn port pin. The Receiver buffer FIFO will be
flushed when the Receiver is disabled. Remaining data in the buffer will be lost
19.7.7
Flushing the Receive Buffer
The receiver buffer FIFO will be flushed when the Receiver is disabled, i.e., the buffer will be
emptied of its contents. Unread data will be lost. If the buffer has to be flushed during normal
operation, due to for instance an error condition, read the UDRn I/O location until the RXCn Flag
is cleared. The following code example shows how to flush the receive buffer.
Note:
For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI”
instructions must be replaced with instructions that allow access to extended I/O. Typically
“LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”.
Assembly Code Example
USART_Flush:
sbis
UCSRnA, RXCn
ret
in
r16, UDRn
rjmp
USART_Flush
C Code Example(1)
void
USART_Flush( void )
{
unsigned char
dummy;
while
( UCSRnA & (1<<RXCn) ) dummy = UDRn;
}
相关PDF资料
PIC24F08KL401-I/SO IC MCU 16BIT 8KB FLASH 20-SOIC
PIC18F13K50-I/MQ IC PIC MCU FLASH 512KX8 20-QFN
PIC16F1934-I/PT IC PIC MCU FLASH 256KX7 44-TQFP
PIC24F16KL402-I/SS IC MCU 16BIT 16KB FLASH 28-SSOP
PIC16LF1934-I/PT IC PIC MCU FLASH 256KX7 44-TQFP
PIC16C58B-20/P IC MCU OTP 2KX12 18DIP
PIC18F24K20-I/SP IC PIC MCU FLASH 8KX16 28-DIP
PIC16F1936-I/SP IC PIC MCU FLASH 512KX14 28SPDIP
相关代理商/技术参数
PIC16F1526-I/PT 制造商:Microchip Technology Inc 功能描述:IC 8BIT MCU PIC16F 20 MHz 64-TQFP 制造商:Microchip Technology Inc 功能描述:IC, 8BIT MCU, PIC16F, 20MHz, TQFP-64
PIC16F1526T-I/MR 功能描述:8位微控制器 -MCU 14KB FL 768B RAM 10bit ADC 1.8-5.5V 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
PIC16F1526T-I/PT 功能描述:8位微控制器 -MCU 14KB Flash RAM 768b nanoWatt 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
PIC16F1527-E/MR 功能描述:8位微控制器 -MCU 28KB FL 1536B RAM 10bit ADC 1.8-5.5V 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
PIC16F1527-E/PT 功能描述:8位微控制器 -MCU 14KB Flash RAM 768b nanoWatt 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
PIC16F1527-I/MR 功能描述:8位微控制器 -MCU 28KB FL 1536B RAM 10bit ADC 1.8-5.5V 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
PIC16F1527-I/MR 制造商:Microchip Technology Inc 功能描述:IC 8BIT MCU PIC16F 20 MHz 64-QFN 制造商:Microchip Technology Inc 功能描述:IC, 8BIT MCU, PIC16F, 20 MHz, 64-QFN; Controller Family/Series:PIC16F; Core Size:8bit; No. of I/O's:54; Program Memory Size:28KB; RAM Memory Size:1536Byte; CPU Speed:20MHz; Oscillator Type:External, Internal; No. of Timers:9 ;RoHS Compliant: No
PIC16F1527-I/PT 功能描述:8位微控制器 -MCU 14KB Flash RAM 768b nanoWatt 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