参数资料
型号: XR19L202IL48-F
厂商: Exar Corporation
文件页数: 9/50页
文件大小: 0K
描述: IC UART/TXRX RS232 48QFN
标准包装: 260
特点: *
通道数: 2,DUART
FIFO's: 64 字节
规程: RS232
电源电压: 3.3 V ~ 5 V
带自动流量控制功能:
带IrDA 编码器/解码器:
带故障启动位检测功能:
带调制解调器控制功能:
带CMOS:
安装类型: 表面贴装
封装/外壳: 48-VFQFN 裸露焊盘
供应商设备封装: 48-QFN-EP(7x7)
包装: 托盘
XR19L202
17
REV. 1.0.1
TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
2.15
Sleep Modes and Power-Save Feature with Wake-Up Interrupt
There are three levels of power management integrated in the L202. The device is low power with low
operational and standby supply currents. In the Partial Sleep mode, the internal oscillator of the UART or
charge pump of the RS-232 transceiver is turned off to reduce the power consumption. In the Full Sleep mode,
both the oscillator and the charge pump are turned off. The Power-save mode provides additional power
saving by isolating the UART address, data and control signals during Sleep mode to minimize the power
consumption.
2.15.1
Partial Sleep Mode
There are two different partial sleep modes. In the first mode, the UART is in sleep mode and the charge pump
is active. In the other mode, the UART is still active but the charge pump is turned off.
2.15.1.1
UART in sleep mode, RS-232 transceiver active
If the ACP pin is LOW, then the charge pump for the RS-232 transceiver will always be active. But the UART
portion in the L202 can still enter sleep mode if all of these conditions are satisfied:
no interrupts pending (ISR bit-0 = 1)
the 16-bit divisor programmed in DLM and DLL registers is a non-zero value
sleep mode is enabled (IER bit-4 = 1)
modem inputs are not toggling (MSR bits 0-3 = 0)
RXD input pin is idling LOW
The L202 stops its crystal oscillator to conserve power in this mode. The user can check the XTAL2 pin for no
clock output as an indication that the device has entered the partial sleep mode.
The UART portion in the L202 resumes normal operation or active mode by any of the following:
a receive data start bit transition on the RXD input (LOW to HIGH)
a data byte is loaded to the transmitter, THR or FIFO
a change of logic state on any of the modem or general purpose serial inputs: i.e., any of the MSR bits 0-
3 shows a ’1’
If the sleep mode is enabled and the L202 is awakened by one of the conditions described above, an interrupt
is issued by the L202 to signal to the CPU that it is awake. The lower nibble of the interrupt source register
(ISR) will read a value of 0x1 for this interrupt and reading the ISR clears this interrupt. Since the same value
(0x1) is also used to indicate no pending interrupt, users should exercise caution while using the sleep mode.
The UART portion in the L202 will return to the sleep mode automatically after all interrupting conditions have
been serviced and cleared. If the UART portion of the L202 is awakened by the modem inputs, a read to the
MSR is required to reset the modem inputs. In any case, the sleep mode will not be entered while an interrupt
is pending. The UART portion of the L202 will stay in the sleep mode of operation until it is disabled by setting
IER bit-4 to a logic 0.
相关PDF资料
PDF描述
XR19L210IL40-F IC UART/TXRX RS232 40QFN
XR19L212IL48-F IC UART/TXRX RS232 48QFN
XR19L220IL40-F IC UART/TXRX RS232 40QFN
XR19L222IL64-F IC UART/TXRX RS232 64QFN
XR19L400IL40-F IC UART/TXRX RS485 40QFN
相关代理商/技术参数
参数描述
XR19L210 制造商:EXAR 制造商全称:EXAR 功能描述:SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
XR19L210_07 制造商:EXAR 制造商全称:EXAR 功能描述:SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
XR19L210IL40 制造商:EXAR 制造商全称:EXAR 功能描述:SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
XR19L210IL40-0A-EB 功能描述:界面开发工具 Supports L210 40 pin QFN, ISA Interface RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V
XR19L210IL40-0B-EB 功能描述:界面开发工具 Supports L210 40 pin QFN, PCI Interface RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V