XR17D154IV-F Exar Corporation, XR17D154IV-F Datasheet - Page 19

• Manufacturer Part Number: XR17D154IV-F
• Description: IC UART PCI BUS QUAD 144LQFP
• Manufacturer: Exar Corporation
• Type: IrDA or RS- 485r

Specifications of XR17D154IV-F

• Number Of Channels: 4, QUART
• Package / Case: 144-LQFP
• Features: *
• Fifo's: 64 Byte
• Protocol: RS485
• Voltage - Supply: 3.3V, 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): 5.5 V
• Supply Voltage (min): 3 V
• Supply Current: 4 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 3.3 V or 5 V
• No. Of Channels: 4
• Uart Features: Tx/Rx FIFO Counters
• Supply Voltage Range: 3V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• 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: 1016-1290

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REV. 1.2.2
Each UART can be separately enabled to enter Sleep mode through the Sleep register. Sleep mode reduces
power consumption when the system needs to put the UART(s) to idle. All of these conditions must be satisfied
for the D154 to enter sleep mode:
The D154 stops its crystal oscillator to conserve power in the sleep mode. User can check the XTAL2 pin for
no clock output as an indication that the device has entered the sleep mode.
The D154 resumes normal operation by any of the following:
If the D154 is awakened by any one of the above conditions, it will return to the sleep mode automatically after
all interrupting conditions have been serviced and cleared. If the D154 is awakened by the modem inputs, a
read 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 from any channel. The D154 will stay in the sleep mode of operation until it is disabled
by setting Sleep = 0x00. In this case, the quad UART is awaken by any of the UART channel from a receive
data byte or a change on the serial port. The UART is ready after 32 crystal clocks to ensure full functionality.
Also, a special interrupt is generated with an indication of no pending interrupt. Reading INT0 will clear this
special interrupt. Logic 0 (default) is disable and logic 1 is enable to sleep mode.
Important: The XR17D154 is a versatile device designed to operate with different VCC (core power supply)
and VIO(PCI bus I/O power supply). However, the VCC and VIO must be equal (VCC = VIO) for the sleep
mode to reduce power consumption. Any difference in these voltages will result in high currents, when placed
in sleep mode. If sleep mode is used, it is recommended that both VCC and VIO be powered by the PCI bus
VIO power pins. If sleep mode is not used, there is no concern about high currents whether VCC = VIO or VCC
> VIO. In any case, VCC should never be less than VIO.
2.2.6
• no interrupts pending (INT0 = 0x00)
• divisor is a non-zero value for all channels (ie. DLL = 0x1)
• sleep mode is enabled (SLEEP = 0x0F)
• modem inputs for all channels are not toggling (MSR bits 0-3 = 0)
• RX input pins for all channels are idling HIGH
• a receive data start bit transition (HIGH to LOW)
• a data byte is loaded to the transmitter, THR or FIFO
• a change of logic state on any of the modem or general purpose serial inputs: CTS#, DSR#, CD#, RI#
SLEEP [31:24] - (default 0x00)
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
Rsvd
Individual UART Channel Sleep Enable
Rsvd Rsvd Rsvd
SLEEP Register
19
Ch-3 Ch-2 Ch-1 Ch-0
UNIVERSAL (3.3V AND 5V) PCI BUS QUAD UART
XR17D154