XR17D152 Datasheet, PDF (5/68 Pages) Exar Corporation – UNIVERSAL (3.3V AND 5V) PCI BUS DUAL UART

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REV. 1.2.0
XR17D152
UNIVERSAL (3.3V AND 5V) PCI BUS DUAL UART
PIN DESCRIPTIONS
NAME
PIN #
TYPE
DESCRIPTION
TMRCK
ENIR
EN485#
TEST#
75
I 16-bit timer/counter external clock input.
74
I ^{Global Infrared mode enable (active high). This pin is sampled during power}
up, following a hardware reset (RST#) or soft-reset (register RESET). It can
be used to start up both UARTs in the infrared mode. The sampled logic state
is transferred to MCR bit-6 in the UART. Software can override this pin there-
after and enable or disable it.
65
I ^{Global AutoRS485 half-duplex direction control enable (active low). During}
power up or reset, this pin is sampled and if it is a logic high, both UARTs are
set for Auto RS485 Mode. Also, the Auto RS485 bit, FCTR[5], is set in both
channels. Software can override this pin thereafter and enable or disable it.
79
I Factory Test. Connect to VCC for normal operation.
VCC
54, 80
PWR
5V or 3.3V power supply for the core logic. This power supply determines
the VOH level of the non-PCI bus interface outputs. Note that VCC ≥ VIO for
normal device operation. See “Application Examples” on page 7. However,
VCC must equal VIO if sleep mode is used. See Sleep Mode section on
page 18.
VIO
10, 22, 32, 43, PWR PCI bus I/O power supply - 3.3V or 5V, detected by the auto-sense circuitry of
89, 100
the XR17D152. This power supply determines the VOH level of the PCI bus
interface outputs.
(PCI 2.3 signalling compliant at both 3.3V and 5V operation, suitable for uni-
versal form factor add-in card application.)
GND
1, 11, 23, 33, PWR Power supply common, ground.
44, 53, 78, 88
NC
63, 64
No Connection.
NOTE: Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
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