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XR17C158
xr
5V PCI BUS OCTAL UART
REV. 1.4.3
6
NOTE: Pin type: I=Input, O=Output, IO= Input/output, OD=Output Open Drain.
EECS
115
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 resistor for exter-
nal sensing of EEPROM during power up. See DAN112 for further details.
EEDI
114
O
Write data to EEPROM device. It is manually accessible thru the Configura-
tion Register REGB.
EEDO
113
I
Read data from EEPROM device. It is manually accessible thru the Configu-
ration Register REGB.
XTAL1
110
I
Crystal or external clock input.
XTAL2
109
O
Crystal or buffered clock output.
TMRCK
69
I
16-bit timer/counter external clock input.
ENIR
70
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 8 UARTs in the infrared mode. The sampled logic state is trans-
ferred to MCR bit-6 in the UART.
TEST#
111
I
Factory Test. Connect to VCC for normal operation.
VCC
4,19,34,45,64,
90,112,137
+5V power supply. For a pin-to-pin compatible device that operates at 3.3V,
see the XR17D158.
GND
5,20,35,46,63,
89,136
Power supply common, ground.
Pin Description
NAME
PIN #TYPE
DESCRIPTION