參數(shù)資料
型號: XRT16C854
廠商: Exar Corporation
英文描述: 2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
中文描述: 2.97V至5.5V四路UART的128字節(jié)FIFO
文件頁數(shù): 14/54頁
文件大小: 485K
代理商: XRT16C854
XR16C854/854D
2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
xr
REV. 3.0.1
14
2.11
The transmitter section comprises of an 8-bit Transmit Shift Register (TSR) and 128 bytes of FIFO which
includes a byte-wide Transmit Holding Register (THR). TSR shifts out every data bit with the 16X internal
clock. A bit time is 16 clock periods. The transmitter sends the start-bit followed by the number of data bits,
inserts the proper parity-bit if enabled, and adds the stop-bit(s). The status of the TX FIFO and TSR are
reported in the Line Status Register (LSR bit-5 and bit-6).
2.11.1
Transmit Holding Register (THR) - Write Only
The transmit holding register is an 8-bit register providing a data interface to the host processor. The host
writes transmit data byte to the THR to be converted into a serial data stream including start-bit, data bits,
parity-bit and stop-bit(s). The least-significant-bit (Bit-0) becomes first data bit to go out. The THR is the input
register to the transmit FIFO of 128 bytes when FIFO operation is enabled by FCR bit-0. Every time a write
operation is made to the THR, the FIFO data pointer is automatically bumped to the next sequential data
location.
2.11.2
Transmitter Operation in non-FIFO Mode
The host loads transmit data to THR one character at a time. The THR empty flag (LSR bit-5) is set when the
data byte is transferred to TSR. THR flag can generate a transmit empty interrupt (ISR bit-1) when it is enabled
by IER bit-1. The TSR flag (LSR bit-6) is set when TSR becomes completely empty.
Transmitter
F
IGURE
6. B
AUD
R
ATE
G
ENERATOR
AND
P
RESCALER
T
ABLE
6: T
YPICAL
DATA
RATES
WITH
A
14.7456 MH
Z
CRYSTAL
OR
EXTERNAL
CLOCK
O
UTPUT
Data Rate
MCR Bit-7=1
O
UTPUT
Data Rate
MCR Bit-7=0
(D
EFAULT
)
D
IVISOR
FOR
16x
Clock (Decimal)
D
IVISOR
FOR
16x
Clock (HEX)
DLM
P
ROGRAM
V
ALUE
(HEX)
DLL
P
ROGRAM
V
ALUE
(HEX)
D
ATA
R
ATE
E
RROR
(%)
100
600
1200
2400
4800
9600
19.2k
38.4k
57.6k
115.2k
230.4k
400
2400
4800
9600
19.2k
38.4k
76.8k
153.6k
230.4k
460.8k
921.6k
2304
384
192
96
48
24
12
6
4
2
1
900
180
C0
60
30
18
0C
06
04
02
01
09
01
00
00
00
00
00
00
00
00
00
00
80
C0
60
30
18
0C
06
04
02
01
0
0
0
0
0
0
0
0
0
0
0
XTAL1
XTAL2
Crystal
Osc/
Buffer
MCR Bit-7=0
(default)
MCR Bit-7=1
DLL and DLM
Registers
Prescaler
Divide by 1
Prescaler
Divide by 4
16X
Sampling
Rate Clock to
Transmitter
Baud Rate
Generator
Logic
相關PDF資料
PDF描述
XRT16L2552 2.25V TO 5.5V DUART WITH 16-BYTE FIFO
XRT3591 SINGLECHIP V. 35 TRANSCEIVER
XRT3591B SINGLECHIP V. 35 TRANSCEIVER
XRT3591BID SINGLECHIP V. 35 TRANSCEIVER
XRT3591BIP SINGLECHIP V. 35 TRANSCEIVER
相關代理商/技術參數(shù)
參數(shù)描述
XRT16L2552 制造商:EXAR 制造商全稱:EXAR 功能描述:2.25V TO 5.5V DUART WITH 16-BYTE FIFO
XRT2588CN 制造商:Exar Corporation 功能描述:
XR-T2713CP 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Subscriber Line Metering/Monitoring Circuit
XR-T3588 制造商:EXAR 制造商全稱:EXAR 功能描述:V.35 Interface Receiver/Transmitter
XR-T3588-89ES 制造商:EXAR 制造商全稱:EXAR 功能描述:XR-T3588/89 Evaluation System