參數(shù)資料
型號(hào): SCC2691
廠商: NXP Semiconductors N.V.
英文描述: Universal asynchronous receiver/transmitter (DUART)(通用異步接收器/傳送器)
中文描述: 通用異步接收器/發(fā)送器(杜阿爾特)(通用異步接收器/傳送器)
文件頁(yè)數(shù): 20/24頁(yè)
文件大?。?/td> 168K
代理商: SCC2691
Philips Semiconductors
Product specification
SCC2691
Universal asynchronous receiver/transmitter (UART)
1998 Sep 04
20
Table 6.
Baud Rates Extended
Normal BRG
BRG Test
CSR[7:4]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
ACR[7] = 0
50
110
134.5
200
300
600
1,200
1,050
2,400
4,800
7,200
9,600
38.4K
Timer
I/O2 – 16X
I/O2 – 1X
ACR[7] = 1
75
110
134.5
150
300
600
1,200
2,000
2,400
4,800
1,800
9,600
19.2K
Timer
I/O2 – 16X
I/O2 – 1X
ACR[7] = 0
4,800
880
1,076
19.2K
28.8K
57.6K
115.2K
1,050
57.6K
4,800
57.6K
9,600
38.4K
Timer
I/O2 – 16X
I/O2 – 1X
ACR[7] = 1
7,200
880
1,076
14.4K
28.8K
57.6K
115.2K
2,000
57.6K
4,800
14.4K
9,600
19.2K
Timer
I/O2 – 16X
I/O2 – 1X
NOTE:
Each read on address H‘2’ will toggle the baud rate test mode. When in the BRG test mode, the baud rates change as shown to the left. This
change affects all receivers and transmitters on the DUART. See “Extended baud rates for SCN2681, SCN68681, SCC2691, SCC2692,
SCC68681 and SCC2698B”in application notes elsewhere in this publication.
The test mode at address H‘A’ changes all transmitters and receivers to the 1x mode and connects the output ports to some internal nodes.
A condition that occurs infrequently has been observed where the receiver will ignore all data. It is caused by a corruption of the start bit
generally due to noise. When this occurs the receiver will appear to be asleep or locked up. The receiver must be reset for the UART to
continue to function properly.
Reset in the Normal Mode (Receiver Enabled)
Recovery can be accomplished easily by issuing a receiver software reset followed by a receiver enable. All receiver data, status and
programming will be preserved and available before reset. The reset will NOT affect the programming.
Reset in the Wake-Up Mode (MR1[4:3] = 11)
Recovery can also be accomplished easily by first exiting the wake-up mode (MR1[4:3] = 00 or 01 or 10), then issuing a receiver software
reset followed by a wake-up re-entry (MR1[4:3] = 11). All receiver data, status and programming will be preserved and available before
reset. The reset will NOT affect the programming.
The receiver has a digital filter designed to reject “noisy” data transitions and the receiver state machine was designed to reject noisy start
bits or noise that might be considered a start bit. In spite of these precautions, corruption of the start bit can occur in 15ns window
approximately 100ns prior to the rising edge of the data clock. The probability of this occurring is less than 10
–5
at 9600 baud.
A corrupted start bit may have some deleterious effects in ASYNC operation if it occurs within a normal data block. The receiver will tend
to align its data clock to the next ‘0’ bit in the data stream, thus potentially corrupting the remainder of the data block. A good design
practice, in environments where start bit corruption is possible, is to monitor data quality (framing error, parity error, break change and
received break) and “data stopped” time out periods. Time out periods can be enabled using the counter/timer in the SCC2691, SCC2692,
SCC2698B and SC68692 products. This monitoring can indicate a potential start bit corruption problem.
SD00097
相關(guān)PDF資料
PDF描述
SCC2692 Dual universal asynchronous receiver/transmitter (DUART)(雙通用異步接收器/傳送器)
SCC2698A Enhanced Octal Universal Asynchronous Receiver/Transmitter (Octal UART)(增強(qiáng)型八路通用異步接收器/傳送器)
SCC2698B Enhanced octal universal asynchronous receiver/transmitter (Octal UART)(增強(qiáng)型八通用異步接收器/傳送器)
SCC68070 16/32-bit microprocessor
SCC68070ABA84 16/32-bit microprocessor
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SCC2691AC1A28 功能描述:UART 接口集成電路 5V INDSTRL UART 1 C RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 數(shù)據(jù)速率:3 Mbps 電源電壓-最大:3.6 V 電源電壓-最小:2.7 V 電源電流:20 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LQFP-48 封裝:Reel
SCC2691AC1A28,129 制造商:NXP Semiconductors 功能描述:PHASCC2691AC1A28.129 ASYNCH RCVR/XMITTER 制造商:NXP Semiconductors 功能描述:1 Tube
SCC2691AC1A28,512 功能描述:UART 接口集成電路 UART RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 數(shù)據(jù)速率:3 Mbps 電源電壓-最大:3.6 V 電源電壓-最小:2.7 V 電源電流:20 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LQFP-48 封裝:Reel
SCC2691AC1A28,518 功能描述:UART 接口集成電路 UART RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 數(shù)據(jù)速率:3 Mbps 電源電壓-最大:3.6 V 電源電壓-最小:2.7 V 電源電流:20 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LQFP-48 封裝:Reel
SCC2691AC1A28,602 功能描述:UART 接口集成電路 5V INDSTRL UART 1 C RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 數(shù)據(jù)速率:3 Mbps 電源電壓-最大:3.6 V 電源電壓-最小:2.7 V 電源電流:20 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LQFP-48 封裝:Reel