- 您现在的位置：买卖IC网 > Sheet目录323 > EFM32G-DK3550 (Energy Micro)KIT DEVELOPMENT EFM32 GECKO
...the world's most energy friendly microcontrollers
16.3.4 PRS-triggered Transmissions
If a transmission must be started on an event with very little delay, the PRS system can be used
to trigger the transmission. The PRS channel to use as a trigger can be selected using TSEL in
USARTn_TRIGCTRL. When a positive edge is detected on this signal, the receiver is enabled if RXTEN
in USARTn_TRIGCTRL is set, and the transmitter is enabled if TXTEN in USARTn_TRIGCTRL is set.
Only one signal input is supported by the USART.
16.3.5 DMA Support
The USART has full DMA support. The DMA controller can write to the transmit buffer using the
registers USARTn_TXDATA, USARTn_TXDATAX, USARTn_TXDOUBLE and USARTn_TXDOUBLEX,
and it can read from the receive buffer using the registers USARTn_RXDATA, USARTn_RXDATAX,
USARTn_RXDOUBLE and USARTn_RXDOUBLEX. This enables single byte transfers, 9 bit data +
control/status bits, double byte and double byte + control/status transfers both to and from the USART.
A request for the DMA controller to read from the USART receive buffer can come from the following
source:
? Data available in the receive buffer
A write request can come from one of the following sources:
? Transmit buffer and shift register empty. No data to send.
? Transmit buffer has room for more data
Even though there are two sources for write requests to the DMA, only one should be used at a time,
since the requests from both sources are cleared even though only one of the requests are used.
In some cases, it may be sensible to temporarily stop DMA access to the USART when an error such
as a framing error has occurred. This is enabled by setting ERRSDMA in USARTn_CTRL.
16.3.6 Transmission Delay
By configuring TXDELAY in USARTn_CTRL, the transmitter can be forced to wait a number of bit-
periods from it is ready to transmit data, to it actually transmits the data. This delay is only applied to the
first frame transmitted after the transmitter has been idle. When transmitting frames back-to-back the
delay is not introduced between the transmitted frames.
This is useful on half duplex buses, because the receiver always returns received frames to software
during the first stop-bit. The bus may still be driven for up to 3 baud periods, depending on the current
frame format. Using the transmission delay, a transmission can be started when a frame is received,
and it is possible to make sure that the transmitter does not begin driving the output before the frame
on the bus is completely transmitted.
TXDELAY in USARTn_CTRL only applies to asynchronous transmission.
16.3.7 Interrupts
The interrupts generated by the USART are combined into two interrupt vectors. Interrupts related to
reception are assigned to one interrupt vector, and interrupts related to transmission are assigned to
the other. Separating the interrupts in this way allows different priorities to be set for transmission and
reception interrupts.
The transmission interrupt vector groups the transmission-related interrupts generated by the following
interrupt flags:
? TXC
? TXBL
2011-04-12 - d0001_Rev1.10
196
www.energymicro.com
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
EFM32GG-STK3700
KIT STARTER GIANT GECKO
EFM32LG-DK3650
KIT DEV EFM32 LEOPARD GECKO
EK-K7-KC705-CES-G-J
KINTEX-7 FPGA KC705 EVAL KIT
EK-S6-SP601-G
KIT EVAL SPARTAN 6 SP601
EK-S6-SP605-G
KIT EVAL SPARTAN 6 SP605
EK-V6-ML631-G-J
VIRTEX-6 HXT FPGA ML631 EVAL KIT
EK-V7-VC707-CES-G
VIRTEX-7 VC707 EVAL KIT
EK-Z7-ZC702-CES-G
ZYNQ-7000 EPP ZC702 EVAL KIT
相关代理商/技术参数
EFM32GG230F1024
功能描述:ARM微控制器 - MCU 1024KB FL 128KB RAM
RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 处理器系列:STM32F373xx 数据总线宽度:32 bit 最大时钟频率:72 MHz 程序存储器大小:256 KB 数据 RAM 大小:32 KB 片上 ADC:Yes 工作电源电压:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LQFP-48 安装风格:SMD/SMT
EFM32GG230F1024G-E-QFN64R
功能描述:IC MCU 32BIT 1MB FLASH 64QFN 制造商:silicon labs 系列:Giant Gecko 包装:剪切带（CT） 零件状态:在售 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:48MHz 连接性:I2C，IrDA，智能卡，SPI，UART/USART 外设:欠压检测/复位，DMA，POR，PWM，WDT I/O 数:56 程序存储容量:1MB（1M x 8） 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:128K x 8 电压 - 电源（Vcc/Vdd）:1.98 V ~ 3.8 V 数据转换器:A/D 8x12b，D/A 2x12b 振荡器类型:内部 工作温度:-40°C ~ 85°C（TA） 封装/外壳:64-VFQFN 裸露焊盘 供应商器件封装:64-QFN（9x9） 标准包装:1
EFM32GG230F1024-QFN64
制造商:Energy Micro AS 功能描述:GIANT GECKO MCU - Cut TR (SOS) 制造商:Energy Micro 功能描述:GIANT GECKO MCU 制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32GG230F1024-QFN64T
制造商:Energy Micro AS 功能描述:GIANT GECKO MCU - Trays
EFM32GG230F1024-QFN64-T
制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32-GG230F1024-SK
制造商:Energy Micro AS 功能描述:GIANT GECKO SAMPLE KIT - Bulk
EFM32GG230F1024-T
制造商:Energy Micro AS 功能描述:IC MCU 32BIT 1MB FLASH 64QFN
EFM32GG230F512
功能描述:ARM微控制器 - MCU 512KB FL 128KB RAM
RoHS:否 制造商:STMicroelectronics 核心:ARM Cortex M4F 处理器系列:STM32F373xx 数据总线宽度:32 bit 最大时钟频率:72 MHz 程序存储器大小:256 KB 数据 RAM 大小:32 KB 片上 ADC:Yes 工作电源电压:1.65 V to 3.6 V, 2 V to 3.6 V, 2.2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:LQFP-48 安装风格:SMD/SMT