XR16M752 Datasheet, PDF (6/51 Pages) Exar Corporation – HIGH PERFORMANCE DUART WITH 64-BYTE FIFO

XR16M752/XR68M752
HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
Pin Description
REV. 1.0.2
NAME
OP2B#
32-QFN
PIN #
-
48-TQFP
PIN #
9
TYPE
DESCRIPTION
O _{Output Port 2 Channel B - The output state is defined by the user and}
through the software setting of MCR[3]. INTB is set to the active mode
and OP2B# output LOW when MCR[3] is set to a logic 1. INTB is set to
the three state mode and OP2B# output HIGH when MCR[3] is set to a
logic 0. See MCR[3]. If INTB is used, this output should not be used as
a general output else it will disturb the INTB output functionality.
ANCILLARY SIGNALS
XTAL1
10
13
XTAL2
11
14
I _{Crystal or external clock input.}
O _{Crystal or buffered clock output.}
16/68#
17
24
I Intel or Motorola Bus Select (internal pull-up resistor). This pin is not
available for the XR16M752. This pin is available for the XR68M752
only.
When 16/68# pin is HIGH, 16 or Intel Mode, the device will operate in
the Intel bus type of interface.
When 16/68# pin is LOW, 68 or Motorola mode, the device will operate
in the Motorola bus type of interface.
RESET
24
36
(RESET#)
VCC
26
42
GND
13
17
GND Center Pad
-
NC
9
12, 25, 37
I When 16/68# pin is HIGH for Intel bus interface, this input becomes
RESET (active high). When 16/68# pin is LOW for Motorola bus inter-
face, this input becomes RESET# (active low).
A 40 ns minimum active pulse on this pin will reset the internal registers
and all outputs of channel A and B. The UART transmitter output will be
held HIGH, the receiver input will be ignored and outputs are reset dur-
ing reset period (see Table 16).
Pwr _{1.62V to 3.63V power supply.}
Pwr _{Power supply common, ground.}
Pwr _{The center pad on the backside of the QFN package is metallic and}
should be connected to GND on the PCB. The thermal pad size on the
PCB should be the approximate size of this center pad and should be
solder mask defined. The solder mask opening should be at least
0.0025" inwards from the edge of the PCB thermal pad.
No Connection.
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
6