XR16C864IQ-F Exar Corporation, XR16C864IQ-F Datasheet - Page 20

• Manufacturer Part Number: XR16C864IQ-F
• Description: IC UART FIFO 128B QUAD 100QFP
• Manufacturer: Exar Corporation
• Type: Quad UART with 128-byte FIFOsr

Specifications of XR16C864IQ-F

• Number Of Channels: 4, QUART
• Package / Case: 100-BQFP
• Features: *
• Fifo's: 128 Byte
• Protocol: RS232, RS485
• Voltage - Supply: 2.97 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
• Data Rate: 2 Mbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.97 V
• Supply Current: 3 mA to 6 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 2.97 V to 5.5 V
• No. Of Channels: 4
• Uart Features: Tx/Rx FIFO Counters
• Supply Voltage Range: 2.97V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: QFP
• 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: 1016-1277

XR16C864
2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
to the MSR is required to reset the modem inputs. In any case, the sleep mode will not be entered while an
interrupt is pending in any channel. The 864 will stay in the sleep mode of operation until it is disabled by
setting IER bit-4 to a logic 0.
If the address lines, data bus lines, IOW#, IOR#, CSA#, CSB#, CSC#, CSD# and modem input lines remain
steady when the 864 is in sleep mode, the maximum current will be in the microamp range as specified in the
DC Electrical Characteristics on
mode, the current can be up to 100 times more. If any of those signals are toggling or floating, then an external
buffer would be required to keep the address, data and control lines steady to achieve the low current.
A word of caution: owing to the starting up delay of the crystal oscillator after waking up from sleep mode, the
first few receive characters may be lost. Also, make sure the RX input is idling at logic 1 or “marking” condition
during sleep mode. This may not occur when the external interface transceivers (RS-232, RS-485 or another
type) are also put to sleep mode and cannot maintain the “marking” condition. To avoid this, the system design
engineer can use a 47k ohm pull-up resistor on the RX A-D inputs.
The 864 UART provides an internal loopback capability for system diagnostic purposes. The internal loopback
mode is enabled by setting MCR register bit-4 to logic 1. All regular UART functions operate normally.
Figure 12
output is internally routed to the receive shift register input allowing the system to receive the same data that it
was sending. The TX pin is held at logic 1 or mark condition while RTS# and DTR# are de-asserted, and
CTS#, DSR# CD# and RI# inputs are ignored. Caution: the RX input must be held to a logic 1 during loopback
test else upon exiting the loopback test the UART may detect and report a false “break” signal.
2.22
Internal Loopback
shows how the modem port signals are re-configured. Transmit data from the transmit shift register
page
40. If the input lines are floating or are toggling while the 864 is in sleep
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REV. 2.0.1