参数资料
| 型号： | SCC2681AC1N40,112 |
| 厂商： | NXP Semiconductors |
| 文件页数： | 6/29页 |
| 文件大小： | 0K |
| 描述： | IC UART DUAL 40-DIP |
| 产品培训模块： | Stand-Alone UARTs |
| 标准包装： | 9 |
| 特点： | 故障启动位检测 |
| 通道数： | 2，DUART |
| FIFO's： | 3 位 |
| 电源电压： | 5V |
| 带并行端口： | 是 |
| 带自动流量控制功能： | 是 |
| 带故障启动位检测功能： | 是 |
| 带CMOS： | 是 |
| 安装类型： | 通孔 |
| 封装/外壳： | 40-DIP（0.600"，15.24mm） |
| 供应商设备封装： | 40-DIP |
| 包装： | 管件 |
| 其它名称： | 568-3525-5 935274523112 SCC2681AC1N40 |
第1页第2页第3页第4页第5页当前第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页
Philips Semiconductors
Product data
SCC2681
Dual asynchronous receiver/transmitter (DUART)
2004 Apr 06
14
MR1A – Channel A Mode Register 1
MR1A is accessed when the Channel A MR pointer points to MR1.
The pointer is set to MR1 by RESET or by a ‘set pointer’ command
applied via CRA. After reading or writing MR1A, the pointer will point
to MR2A.
MR1A[7] – Channel A Receiver Request-to-Send Flow Control
This bit controls the deactivation of the RTSAN output (OP0) by the
receiver. This output is normally asserted by setting OPR[0] and
negated by resetting OPR[0]. MR1A[7] = 1 causes RTSAN to be
negated upon receipt of a valid start bit if the Channel A FIFO is full.
However, OPR[0] is not reset and RTSAN will be asserted again
when an empty FIFO position is available. This feature can be used
for flow control to prevent overrun in the receiver by using the
RTSAN output signal to control the CTSN input of the transmitting
device.
MR1A[6] – Channel A Receiver Interrupt Select
This bit selects either the Channel A receiver ready status (RxRDY)
or the Channel A FIFO full status (FFULL) to be used for CPU
interrupts. It also causes the selected bit to be output on OP4 if it is
programmed as an interrupt output via the OPCR.
MR1A[5] – Channel A Error Mode Select
This bit select the operating mode of the three FIFOed status bits
(FE, PE, received break) for Channel A. In the ‘character’ mode,
status is provided on a character-by-character basis; the status
applies only to the character at the top of the FIFO. In the ‘block”
mode, the status provided in the SR for these bits is the
accumulation (logical-OR) of the status for all characters coming to
the top of the FIFO since the last ‘reset error’ command for Channel
A was issued.
MR1A[4:3| – Channel A Parity Mode Select
If ‘with parity’ or ‘force parity’ is selected a parity bit is added to the
transmitted character and the receiver performs a parity check on
incoming data MR1A[4:3] + 11 selects Channel A to operate in the
special multidrop mode described in the Operation section.
MR1A[2] – Channel A Parity Type Select
Note: Setting these bits to ‘11’ causes a partial enabling of the
receiver. Set these bits to other than ‘11’ if a software or hardware
reset is required for some type of error recovery.
This bit selects the parity type (odd or even) if the ‘with parity’ mode
is programmed by MR1A[4:3], and the polarity of the forced parity bit
if the ‘force parity’ mode is programmed. It has no effect if the ‘no
parity’ mode is programmed. In the special multidrop mode it selects
the polarity of the A/D bit.
MR1A[1:0] – Channel A Bits Per Character Select
This field selects the number of data bits per character to be
transmitted and received. The character length does not include the
start, parity, and stop bits.
MR2A – Channel A Mode Register 2
MR2A is accessed when the Channel A MR pointer points to MR2,
which occurs after any access to MR1A. Accesses to MR2A do not
change the pointer.
MR2A[7:6] – Channel A Mode Select
Each channel of the DUART can operate in one of four modes.
MR2A[7:6] = 00 is the normal mode, with the transmitter and
receiver operating independently. MR2A[7:6] = 01 places the
channel in the automatic echo mode, which automatically
re-transmits the received data. The following conditions are true
while in automatic echo mode:
1. Received data is re-clocked and retransmitted on the TxDA
output.
2. The receive clock is used for the transmitter.
3. The receiver must be enabled, but the transmitter need not be
enabled.
4. The Channel A TxRDY and TxEMT status bits are inactive.
5. The received parity is checked, but is not regenerated for
transmission, i.e. transmitted parity bit is as received.
6. Character framing is checked, but the stop bits are retransmitted
as received.
7. A received break is echoed as received until the next valid start
bit is detected.
8. CPU to receiver communication continues normally, but the CPU
to transmitter link is disabled.
Two diagnostic modes can also be configured. MR2A[7:6] = 10
selects local loopback mode. In this mode:
1. The transmitter output is internally connected to the receiver
input.
2. The transmit clock is used for the receiver.
3. The TxDA output is held HIGH.
4. The RxDA input is ignored.
5. The transmitter must be enabled, but the receiver need not be
enabled.
6. CPU to transmitter and receiver communications continue
normally.
The second diagnostic mode is the remote loopback mode, selected
by MR2A[7:6] = 11. In this mode:
1. Received data is re-clocked and re-transmitted on the TxDA
output.
2. The receive clock is used for the transmitter.
3. Received data is not sent to the local CPU, and the error status
conditions are inactive.
4. The received parity is not checked and is not regenerated for
transmission, i.e., transmitted parity is as received.
5. The receiver must be enabled.
6. Character framing is not checked and the stop bits are
retransmitted as received.
7. A received break is echoed as received until the next valid start
bit is detected.
The user must exercise care when switching into and out of the
various modes. The selected mode will be activated immediately
upon mode selection, even if this occurs in the middle of a received
相关PDF资料 |
PDF描述 |
|---|---|
| SC16IS760IBS,151 | IC UART I2C/SPI 24-HVQFN |
| XR16C854CJ-F | IC UART FIFO 128B QUAD 68PLCC |
| XR82C684CJ/44-F | IC UART CMOS QUAD 44PLCC |
| XR16C2850IJ-F | IC UART FIFO 128B 44PLCC |
| ST16C554DIJ68-F | IC UART FIFO 16B QUAD 68PLCC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SCC2681AE1A44 | 功能描述:UART 接口集成电路 RPLACMNT FOR SCN2681 RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SCC2681AE1A44,512 | 功能描述:UART 接口集成电路 RPLACMNT FOR SCN2681 RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SCC2681AE1A44,518 | 功能描述:UART 接口集成电路 RPLACMNT FOR SCN2681 RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SCC2681AE1A44,529 | 功能描述:UART 接口集成电路 RPLACMNT FOR SCN2681 RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel |
| SCC2681AE1A44512 | 制造商:Rochester Electronics LLC 功能描述: 制造商:NXP Semiconductors 功能描述: |
发布紧急采购，3分钟左右您将得到回复。