XR16L570IL24-F Exar Corporation, XR16L570IL24-F Datasheet - Page 14

• Manufacturer Part Number: XR16L570IL24-F
• Description: 2.25 To 5.5V W/ 5V TOLERANT INPUT UART W/16 BYTE FIFO W/ POWER SAVE
• Manufacturer: Exar Corporation

Specifications of XR16L570IL24-F

• Features: *
• Number Of Channels: 1, UART
• Fifo's: 16 Byte
• Protocol: RS232, RS422
• Voltage - Supply: 1.62 V ~ 5.5 V
• With Auto Flow Control: Yes
• With Irda Encoder/decoder: Yes
• With False Start Bit Detection: Yes
• With Modem Control: Yes
• With Cmos: Yes
• Mounting Type: Surface Mount
• Package / Case: 24-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XR16L570
SMALLEST 1.62V TO 5.5V UART WITH 16-BYTE FIFO AND POWERSAVE
F
IGURE
The local UART (UARTA) starts data transfer by asserting RTSA# (1). RTSA# is normally connected to CTSB# (2) of
remote UART (UARTB). CTSB# allows its transmitter to send data (3). TXB data arrives and fills UARTA receive FIFO
(4). When RXA data fills up to its receive FIFO trigger level, UARTA activates its RXA data ready interrupt (5) and con-
tinues to receive and put data into its FIFO. If interrupt service latency is long and data is not being unloaded, UARTA
monitors its receive data fill level to match the upper threshold of RTS delay and de-assert RTSA# (6). CTSB# follows
(7) and request UARTB transmitter to suspend data transfer. UARTB stops or finishes sending the data bits in its trans-
mit shift register (8). When receive FIFO data in UARTA is unloaded to match the lower threshold of RTS delay (9),
UARTA re-asserts RTSA# (10), CTSB# recognizes the change (11) and restarts its transmitter and data flow again until
next receive FIFO trigger (12). This same event applies to the reverse direction when UARTA sends data to UARTB
with RTSB# and CTSA# controlling the data flow.
11. A
UTO
(RXA FIFO
CTSB#
RXA FIFO
Interrupt)
RTSA#
TXB
INTA
RTS
Trigger Reached
Receiver FIFO
Trigger Level
Local UART
Transmitter
Auto CTS
Auto RTS
UARTA
Monitor
AND
Data Starts
Receive
Data
CTS F
Assert RTS# to Begin
1
2
Transmission
Trigger Level
3
LOW
4
RX FIFO
RTSA#
TXA
CTSA#
RXA
ON
C
ON
ONTROL
5
O
PERATION
7
RTS High
Threshold
14
6
8
OFF
Suspend
OFF
RTSB#
CTSB#
Threshold
RTS Low
RXB
TXB
Restart
9
10
11
Trigger Reached
ON
Remote UART
Trigger Level
Receiver FIFO
12
Auto CTS
Auto RTS
Transmitter
UARTB
Monitor
ON
Trigger Level
RX FIFO
RTSCTS1
REV. 1.0.1