XR17C158CV-F Exar Corporation, XR17C158CV-F Datasheet - Page 19

• 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
The 8-bit Sleep register enables each UART separately to enter Sleep mode. 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 158 to enter sleep mode:
The 158 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 158 resumes normal operation by any of the following:
If the 158 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 158 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 in-
terrupt is pending from any channel. The 158 will stay in the sleep mode of operation until it is disabled by set-
ting Sleep = 0x00. 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) disables the sleep mode and logic 1 enables the sleep mode for each channel. The crystal oscillator
shuts down only when all 8 channels are in sleep mode.
There are two internal registers that provide device identification and revision, DVID and DREV registers. The
8-bit content in the DVID register provides device identification. A return value of 0x28 from this register
indicates the device is a XR17C158. The DREV register returns an 8-bit value of 0x01 for revision A with 0x02
equals to revision B and so forth. This information is very useful to the software driver for identifying which
device it is communicating with and to keep up with revision changes.
DVID [15:8]
Device identification for the type of UART. The upper nibble indicates it is an XR17Cxxx series with lower
nibble indicating the number of channels.
Examples:
XR17C158 or XR17D158 = 0x28
XR17C154 or XR17D154 = 0x24
XR17C152 or XR17D152 = 0x22
DREV [7:0]
Revision number of the XR17C158. A 0x01 represents "revision-A" with 0x02 for rev-B and so forth.
1.2.6 SLEEP [31:24] - (default 0x00)
1.2.7
• no interrupts pending (INT0 = 0x00)
• divisor is a non-zero value for all channels (ie. DLL = 0x1)
• sleep mode is enabled for all 8 channels (SLEEP = 0xFF)
• 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) on the RX input of any channel
• a data byte is loaded to the transmitter, THR or FIFO, of any channel
• a change of logic state on any of the modem or general purpose serial inputs of any channel: CTS#, DSR#,
CD#, RI#
Device Identification and Revision
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
Ch-7
Individual UART Channel Sleep Enable
Ch-6
Ch-5 Ch-4 Ch-3 Ch-2 Ch-1 Ch-0
SLEEP Register
19
5V PCI BUS OCTAL UART
XR17C158