XR17C158CV-F Exar Corporation, XR17C158CV-F Datasheet - Page 32

• 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

XR17C158
5V PCI BUS OCTAL UART
Automatic hardware RTS/CTS or DTR/DSR flow control is used to prevent data overrun to the local receiver
FIFO and remote receiver FIFO. The RTS#/DTR# output pin is used to request the remote unit to suspend/
restart data transmission while the CTS#/DSR# input pin is monitored to suspend/restart the local transmitter.
The auto RTS/CTS or DTR/DSR flow control features are individually selected to fit specific application
requirement and enabled through EFR bit-6 and 7 and MCR bit-2 for either RTS/CTS or DTR/DSR control
signals.
Auto RTS flow control must be started by asserting the RTS# output pin LOW (MCR bit-1 = 1). Similarly, Auto
DTR flow control must be started by asserting the DTR# output pin LOW (MCR bit-0 = 1).
detail how automatic hardware flow control works.
Two interrupts associated with auto RTS/CTS and DTR/DSR flow control have been added to give indication
when RTS#/DTR# pin or CTS#/DSR# pin are de-asserted during operation. These interrupts are enabled by:
•
•
•
Automatic hardware flow control is selected by setting bits 6 (RTS) and 7 (CTS) of the EFR register to logic 1.
If CTS# pin transitions from LOW to HIGH indicating a flow control request, ISR bit-5 will be set to logic 1, (if
enabled via IER bit 6-7), and the UART 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 LOW, indicating more data may
be sent.
4.4
Setting EFR bit-4 =1 to enable the shaded register bits
Setting IER bit-7 will enable the CTS#/DSR# interrupt when these pins are de-asserted. The selection of
CTS# or DSR# is selected via MCR bit-2. See
Setting IER bit-6 will enable the RTS#/DTR# interrupt when these pins are de-asserted. The selection of
RTS# or DTR# is selected via MCR bit-2. See
MCR B
Automatic Hardware (RTS/CTS or DTR/DSR) Flow Control Operation
X
0
0
1
1
IT
-2
T
ABLE
10: A
EFR B
UTO
1
X
1
X
0
IT
-7
RTS/CTS
OR
Table 10
Table 10
DTR/DSR F
EFR B
32
X
X
1
1
0
IT
above for complete details.
above for complete details.
-6
LOW
C
ONTROL
Auto DSR Flow Control Enabled
Auto DTR Flow Control Enabled
Auto CTS Flow Control Enabled
Auto RTS Flow Control Enabled
F
LOW
S
ELECTION
No Flow Control
C
ONTROL
Figure 14
S
ELECTION
xr
REV. 1.4.3
shows in