XR16L570IL24-F Exar Corporation, XR16L570IL24-F Datasheet - Page 9

• 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

REV. 1.0.1
The L570 UART has its own Baud Rate Generator (BRG) with a prescaler. The prescaler is controlled by a
software bit (bit-7) in the MCR register. This bit selects the prescaler to divide the input external clock by a
factor of 1 or 4. The clock output of the prescaler goes to the BRG. The BRG further divides this clock by a
programmable divisor (via DLL and DLM registers) between 1 and (2
of the serial data rate. The sampling rate clock is used by the transmitter for data bit shifting and receiver for
data sampling. The BRG divisor defaults to the maximum baud rate (DLL = 0x01 and DLM = 0x00) upon power
up.
Programming the Baud Rate Generator Registers DLM and DLL provides the capability of selecting the
operating data rate.
sampling rate clock rate. When using a non-standard data rate external clock, the divisor value can be
calculated for DLL/DLM with the following equation.
2.9
Programmable Baud Rate Generator
F
IGURE
CLK
divisor (decimal) = (clock frequency / prescaler) / (serial data rate x 16)
Table 3
6. B
AUD
shows the standard data rates available with a 14.7456 MHz external clock at 16X
Buffer
R
Clock
ATE
G
ENERATOR AND
SMALLEST 1.62V TO 5.5V UART WITH 16-BYTE FIFO AND POWERSAVE
Divide by 4
Divide by 1
Prescaler
Prescaler
P
9
RESCALER
MCR Bit-7=0
MCR Bit-7=1
(default)
Baud Rate
Generator
DLL and DLM
Registers
Logic
16
-1) to obtain a 16X sampling rate clock
Rate Clock to
Transmitter
Sampling
16X
XR16L570