XR17C158CV-F Exar Corporation, XR17C158CV-F Datasheet - Page 33

• Manufacturer Part Number: XR17C158CV-F
• Description: IC UART PCI BUS 5V OCTAL 144LQFP
• Manufacturer: Exar Corporation
• Type: Universal PCI Bus Octal UARTr

Specifications of XR17C158CV-F

• Number Of Channels: 8
• Package / Case: 144-LQFP
• Features: *
• Fifo's: 64 Byte
• Protocol: RS485
• Voltage - Supply: 5V
• With Auto Flow Control: Yes
• With Irda Encoder/decoder: Yes
• With False Start Bit Detection: Yes
• With Modem Control: Yes
• Mounting Type: Surface Mount
• Data Rate: 6.25 Mbps
• Supply Voltage (max): 7 V
• Supply Current: 5 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 7 V
• No. Of Channels: 8
• Uart Features: High Performance, Read/Write Burst Operation
• Supply Voltage Range: -0.5V To 7V
• Operating Temperature Range: 0°C To +70°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1287

xr
REV. 1.4.3
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.
14. A
(RXA FIFO
CTSB#
RXA FIFO
Interrupt)
RTSA#
TXB
INTA
Trigger Reached
UTO
Receiver FIFO
Trigger Level
Local UART
Transmitter
Auto CTS
Auto RTS
UARTA
Monitor
RTS/DTR
Data Starts
Receive
Data
Assert RTS# to Begin
1
AND
2
Transmission
Trigger Level
3
4
RX FIFO
CTS/DSR F
RTSA#
TXA
CTSA#
RXA
ON
ON
LOW
5
7
Threshold
C
RTS High
ONTROL
33
6
8
OFF
Suspend
O
OFF
PERATION
RTSB#
CTSB#
Threshold
RTS Low
RXB
TXB
Restart
9
10
11
Trigger Reached
Remote UART
ON
5V PCI BUS OCTAL UART
Trigger Level
Receiver FIFO
12
Auto CTS
Auto RTS
Transmitter
UARTB
Monitor
ON
Trigger Level
RX FIFO
RTSCTS1
XR17C158