xr20m1280 Exar Corporation, xr20m1280 Datasheet - Page 5

• Manufacturer Part Number: xr20m1280
• Description: I2c/spi Uart With 128-byte Fifo And Integrated Level Shifters
• Manufacturer: Exar Corporation

REV. P1.1.1
Pin Description
ANCILLARY SIGNALS
VCC_CORE
GPIO2/CD#
VCC_UART
GPIO3/RI#
VCC_BUS
PWRDN#
GPIO10
GPIO12
GPIO13
GPIO14
GPIO15
EN485#
GPIO11
SLEEP/
GPIO4
GPIO5
GPIO6
GPIO7
GPIO8
GPIO9
XTAL1
XTAL2
ENIR#
N
AME
QFN-24
P
18
17
22
23
21
10
16
11
IN
8
-
-
-
-
-
-
-
-
-
-
-
-
-
#
QFN-32
PIN#
23
22
20
19
18
17
31
32
10
30
13
21
11
2
-
-
-
-
-
-
-
-
I2C/SPI UART WITH 128-BYTE FIFO AND INTEGRATED LEVEL SHIFTERS
QFN-40
PIN#
31
30
24
23
22
21
15
16
17
18
19
25
26
27
39
40
12
11
38
14
28
2
T
Pwr
Pwr
Pwr
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
YPE
O
I
I
I
General purpose I/O or UART Carrier-Detect (active low).
General purpose I/O or UART Ring-Indicator (active low).
General purpose I/Os.
General purpose I/Os.
Crystal or external clock input. Note: This input is not 5V tolerant.
Crystal or buffered clock output.
Enable Auto RS-485 Half-Duplex Mode. This pin is sampled upon
power-up. If this pin is HIGH, then the RTS# output can be used for
Auto RTS Hardware Flow Control or as a general purpose output. If
this pin is LOW, then the RTS# output is the Auto RS-485 Half-
Duplex direction control pin.
Enable IR Mode. This pin is sampled upon power-up. If this pin is
HIGH, then the TX output and RX input will behave as the UART
transmit data output and UART receive data input. If this pin is
LOW, then the TX output and RX input will behave as the infrared
encoder data output and the infrared receive data input.
Sleep / Power Down pin. This pin powers up as the SLEEP input.
The SLEEP input can force the UART to enter into the sleep mode
after the next byte transmitted or received without meeting any of
the sleep mode conditions.
This pin can also be configured as an output pin which can be used
to indicate to the CPU that the UART has entered the sleep mode.
This output can also be used to power down other devices.
1.62V to 3.63V VCC for the core. This supply voltage is used for the
core logic including the crystal oscillator circuit.
1.62V to 3.63V VCC for bus interface signals.
This supply voltage pin will determine the I/O levels of the CPU bus
interface signals.
1.62V to 3.63V VCC for the UART signals.
This supply voltage pin will determine the I/O levels of the UART I/O
signals including GPIO[3:0].
PRELIMINARY
5
D
ESCRIPTION
XR20M1280