參數(shù)資料
型號: ST16654
廠商: Exar Corporation
英文描述: QUAD UART WITH 64-BYTE FIFO AND INFRARED (IrDA) ENCODER/DECODER
中文描述: 四UART的64字節(jié)FIFO和紅外線(IrDA)編碼/解碼器
文件頁數(shù): 16/49頁
文件大?。?/td> 444K
代理商: ST16654
ST16C654/654D
5-80
Rev. 4.10
FIFO Operation
The 64 byte transmit and receive data FIFO’s are
enabled by the FIFO Control Register (FCR) bit-0.
With 16C554 devices, the user can set the receive
trigger level but not the transmit trigger level. The 654
provides independent trigger levels for both receiver
and transmitter. To remain compatible with
ST16C554, the transmit interrupt trigger level is set to
8 following a reset. It should be noted that the user can
set the transmit trigger levels by writing to the FCR
register, but activation will not take place until EFR bit-
4 is set to a logic 1. The receiver FIFO section includes
a time-out function to ensure data is delivered to the
external CPU. An interrupt is generated whenever the
Receive Holding Register (RHR) has not been read
following the loading of a character or the receive
trigger level has not been reached. (see hardware flow
control for a description of this timing).
Hardware Flow Control
When automatic hardware flow control is enabled, the
654 monitors the -CTS pin for a remote buffer overflow
indication and controls the -RTS pin for local buffer
overflows. Automatic hardware flow control is se-
lected by setting bits 6 (RTS) and 7 (CTS) of the EFR
register to a logic 1. If -CTS transitions from a logic 0
to a logic 1 indicating a flow control request, ISR bit-
5 will be set to a logic 1 (if enabled via IER bit 6-7), and
the 654 will suspend TX transmissions as soon as the
stop bit of the character in process is shifted out.
Transmission is resumed after the -CTS input returns
to a logic 0, indicating more data may be sent.
With the Auto RTS function enabled, an interrupt is
generated when the receive FIFO reaches the pro-
grammed trigger level. The -RTS pin will not be forced
to a logic 1 (RTS Off), until the receive FIFO reaches
the next trigger level
.
However, the -RTS pin will
return to a logic 0 after the data buffer (FIFO) is
unloaded to the next trigger level below the pro-
grammed trigger. However, under the above de-
scribed conditions the 654 will continue to accept data
until the receive FIFO is full.
Selected
Trigger
Level
(characters)
INT
Pin
-RTS
Logic “1”
(characters)
-RTS
Logic “0”
(characters)
Activation
8
16
56
60
8
16
56
60
16
56
60
60
0
8
16
56
相關PDF資料
PDF描述
ST16C1450 2.97V TO 5.5V UART
ST16C1450CJ28 2.97V TO 5.5V UART
ST16C1450CP28 2.97V TO 5.5V UART
ST16C1450CQ48 2.97V TO 5.5V UART
ST16C1450IJ28 2.97V TO 5.5V UART
相關代理商/技術參數(shù)
參數(shù)描述
ST16-683 制造商:RFE 制造商全稱:RFE international 功能描述:TEMPERATURE COMPENSATING THERMISTORS ST Series: Surface Mount
ST1680N 制造商:n/a 功能描述:Diode, Reverse Polarity
ST16C1450 制造商:EXAR 制造商全稱:EXAR 功能描述:2.97V TO 5.5V UART
ST16C1450_05 制造商:EXAR 制造商全稱:EXAR 功能描述:2.97V TO 5.5V UART
ST16C1450CJ28 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: