XR17C154 Datasheet, PDF (5/62 Pages) Exar Corporation – 5V PCI BUS QUAD UART

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REV. 1.3.0
Pin Description
XR17C154
5V PCI BUS QUAD UART
NAME
EECK
EECS
EEDI
EEDO
XTAL1
XTAL2
TMRCK
ENIR
TEST#
VCC
GND
NC
PIN #
116
115
114
113
110
109
69
70
111
4,19,34,45,64,
90,112,137
5,20,35,46,63,
89,136
47-54,
71,72,75-80,
91-98,
117-124
TYPE
DESCRIPTION
O Serial clock to EEPROM. An internal clock of CLK divide by 256 is used for
reading the vendor and sub-vendor ID during power up or reset. However, it
can be manually clocked thru the Configuration Register REGB.
O Chip select to a EEPROM device like 93C46. It is manually selectable thru the
Configuration Register REGB. Requires a pull-up 4.7K ohm resister for exter-
nal sensing of EEPROM during power up. See DAN112 for further details.
O Write data to EEPROM device. It is manually accessible thru the Configura-
tion Register REGB. The 154 auto-configuration register interface logic uses
the 16-bit format.
I Read data from EEPROM device. It is manually accessible thru the Configu-
ration Register REGB.
I Crystal or external clock input of up to 50MHz for data rate of 3.125Mbps at
5V.
O Crystal or buffered clock output.
I 16-bit timer/counter external clock input.
I Infrared mode enable (active high). This pin is sampled during power up, fol-
lowing a hardware reset (RST#) or soft-reset (register RESET). It can be used
to start up all 4 UARTs in the infrared mode. The sampled logic state is trans-
ferred to MCR bit-6 in the UART. Software can override this pin thereafter
and enable or disable it.
I Factory Test. Connect to VCC for normal operation.
PWR +5V (PCI Compliance). For 3.3V operation, see the XR17D154.
PWR Power supply common, ground.
No Connection. These pins are reserved and used by the octal PCI UART
XR17C158.
NOTE: Pin type: I=Input, O=Output, IO= Input/output, OD=Output Open Drain.
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