Exar XR20M1280 User manual

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REV. 1.0.0 XR20M1280 EVALUATION BOARD USER’S MANUAL
INTRODUCTION
This user’s manual is for the XR20M1280 evaluation board. Table 1 shows the different devices and packages
that the evaluation board supports. This user’s manual will describe the hardware setup required to operate the
different packages.
1.0 HARDWARE SETUP
1.1 Packages description
The evaluation board supports all 3 packages of the XR20M1280. The ordering part number, package and
location on the board is shown below in Table 1. Table 2 lists the evaluation board ordering part numbers.
TABLE 1: PACKAGE LIST
ORDERING PART NUMBER PACKAGE LOCATION
XR20M1280IL24-F 24-pin QFN U8
XR20M1280IL32-F 32-pin QFN U9
XR20M1280IL40-F 40-pin QFN U11
TABLE 2: EVALUATION BOARD ORDERING PART NUMBERS
PART NUMBER DEFAULT MODE CONFIGURATION
XR20M1280L24-0A-EB I2C
XR20M1280L24-0B-EB SPI
XR20M1280L32-0A-EB I2C
XR20M1280L32-0B-EB SPI
XR20M1280L40-0A-EB I2C
XR20M1280L40-0B-EB SPI
1.2 Jumper Settings
1.2.1 XR20M1280IL24
The following jumpers apply to the XR20M1280IL24:
TABLE 3: JUMPER SETTINGS FOR XR20M1280IL24
JUMPERS FUNCTIONS COMMENTS
J12 Selects the supply voltage for UART
modem I/Os including GPIO3-GPIO0
(VCC_UART)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J13 Selects the supply voltage for UART core
logic (VCC_CORE)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J14 Selects the supply voltage for CPU bus
interface (VCC_BUS)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V

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XR20M1280 EVALUATION BOARD USER’S MANUAL REV. 1.0.0
J15 Selects the supply voltage for GPIO15-
GPIO4 (VCC_GPIO)
Not used for XR20M1280IL24
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J52 Selects 5V source for regulator to 1.8V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J53 Selects 5V source for regulator to 2.5V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J54 Selects 5V source for regulator to 3.3V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J36 Selects between I2C and SPI mode Jumper in selects SPI mode (default for XR20M1280L24-0B-EB)
Jumper out selects I2C mode (default for XR20M1280L24-0A-EB)
J18 Power for the SP337 RS-232/RS-485
Transceiver
Jumper not installed
Trace between 1&2
J19 Header for RS-485/422 signals RS-485/422 signals are accessible at this header
J20 SP337 Mode Control pins RS-232 Mode - No jumpers installed
RS-485 Mode - Jumpers between 1&2, 5&6
J34 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
J37 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
(Pins 7-10 not used for XR20M1280IL24)
J35 Enable/Disable Auto RS-485 mode at
power-up
(can be enabled/disabled in software after
power-up)
J35 in enables Auto RS-485 mode at power-up
J35 out disables Auto RS-485 mode at power-up
J50 SLEEP/PWRDN pin Header installed, no jumpers installed (default)
Refer to the datasheet for the behavior of this pin
J51 UART Reset input Jumper on 1&2 selects J2 as hardware reset
Jumper on 2&3 selects external reset from J9 pin 32 (default)
J10 I2C Address Select (A0)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
TABLE 3: JUMPER SETTINGS FOR XR20M1280IL24
JUMPERS FUNCTIONS COMMENTS

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REV. 1.0.0 XR20M1280 EVALUATION BOARD USER’S MANUAL
J11 I2C Address Select (A1)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
J9 Header for connection to external micro-
controller board
■Pin 23 = SDA signal for I2C
interface
■Pin 11 = SO signal for SPI
interface
■Pin 19 = IRQ# output signal from
XR20M1170
■Pin 15 = A0 signal for I2C interface
or CS# for SPI interface
■Pin 13 = A1 signal for I2C interface
or SI for SPI interface
■Pin 32 = RESET# input signal
■Pin 9 = SCK for SPI interface
(Jumper on J8 1&2)
■Pin 29 = SCL signal for I2C
interface or (Jumper on J9 2&3)
■Pin 5, 6, 7, 8, 31, 35 = GND signal
■Pin 34 & 36 = External +5V power
Ground and Power connections
■Pin 5, 6, 7, 8, 31 or 35 should be connected to GND
■Pin 34 or 36 should be connected +5V
If I2C interface is used (defaults for XR20M1280IL24-0A-EB):
■Pin 23 should be connected to SDA
■Pin 19 should be connected to MCU interrupt input (if using
interrupts)
■Pin 15 should be unconnected when using J10
■Pin 13 should be unconnected when using J11
■Pin 32 should be connected to the active low reset output
from the MCU
■Pin 29 should be connected to SCL
If SPI interface is used (defaults for XR20M1280IL24-0B-EB):
■Pin 23 should be unconnected
■Pin 11 should be connected to SO
■Pin 19 should be connected to MCU interrupt (if using
interrupts)
■Pin 15 should be connected to CS#
■Pin 13 should be connected to SI
■Pin 32 should be connected to the active low reset output
fromthe MCU
■Pin 9 should be connected to SCK
J39 Routing for GPIO9-13 Not used for XR20M1280IL24
J40 Routing for GPIO8-4 Not used for XR20M1280IL24
TABLE 3: JUMPER SETTINGS FOR XR20M1280IL24
JUMPERS FUNCTIONS COMMENTS

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XR20M1280 EVALUATION BOARD USER’S MANUAL REV. 1.0.0
1.2.2 XR20M1280IL32
The following jumpers apply to the XR20M1280IL32:
TABLE 4: JUMPER SETTINGS FOR XR20M1280IL32
JUMPERS FUNCTIONS COMMENTS
J12 Selects the supply voltage for UART
modem I/Os including GPIO3-GPIO0
(VCC_UART)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J13 Selects the supply voltage for UART core
logic (VCC_CORE)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J14 Selects the supply voltage for CPU bus
interface (VCC_BUS)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J15 Selects the supply voltage for GPIO15-
GPIO4 (VCC_GPIO)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J52 Selects 5V source for regulator to 1.8V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J53 Selects 5V source for regulator to 2.5V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J54 Selects 5V source for regulator to 3.3V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J36 Selects between I2C and SPI mode Jumper in selects SPI mode (default for XR20M1280L32-0B-EB)
Jumper out selects I2C mode (default for XR20M1280L32-0A-EB)
J18 Power for the SP337 RS-232/RS-485
Transceiver
Jumper not installed
Trace between 1&2
J19 Header for RS-485/422 signals RS-485/422 signals are accessible at this header
J20 SP337 Mode Control pins RS-232 Mode - No jumpers installed
RS-485 Mode - Jumpers between 1&2, 5&6
J34 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
J37 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
(Pins 7-10 not used for XR20M1280IL32)
J35 Enable/Disable Auto RS-485 mode at
power-up
(can be enabled/disabled in software after
power-up)
J35 in enables Auto RS-485 mode at power-up
J35 out disables Auto RS-485 mode at power-up
J44 Enable/Disable IR mode at power-up
(can be enabled/disabled in software after
power-up)
J44 in enables IR mode at power-up
J44 out disables IR mode at power-up

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REV. 1.0.0 XR20M1280 EVALUATION BOARD USER’S MANUAL
J50 SLEEP/PWRDN pin Header installed, no jumpers installed (default)
Refer to the datasheet for the behavior of this pin
J51 UART Reset input Jumper on 1&2 selects J2 as hardware reset
Jumper on 2&3 selects external reset from J9 pin 32 (default)
J10 I2C Address Select (A0)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
J11 I2C Address Select (A1)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
J9 Header for connection to external micro-
controller board
■Pin 23 = SDA signal for I2C
interface
■Pin 11 = SO signal for SPI
interface
■Pin 19 = IRQ# output signal from
XR20M1170
■Pin 15 = A0 signal for I2C interface
or CS# for SPI interface
■Pin 13 = A1 signal for I2C interface
or SI for SPI interface
■Pin 32 = RESET# input signal
■Pin 9 = SCK for SPI interface
(Jumper on J8 1&2)
■Pin 29 = SCL signal for I2C
interface or (Jumper on J9 2&3)
■Pin 5, 6, 7, 8, 31, 35 = GND signal
■Pin 34 & 36 = External +5V power
Ground and Power connections
■Pin 5, 6, 7, 8, 31 or 35 should be connected to GND
■Pin 34 or 36 should be connected +5V
If I2C interface is used (defaults for XR20M1280IL32-0A-EB):
■Pin 23 should be connected to SDA
■Pin 19 should be connected to MCU interrupt input (if using
interrupts)
■Pin 15 should be unconnected when using J10
■Pin 13 should be unconnected when using J11
■Pin 32 should be connected to the active low reset output
from the MCU
■Pin 29 should be connected to SCL
If SPI interface is used (defaults for XR20M1280IL32-0B-EB):
■Pin 23 should be unconnected
■Pin 11 should be connected to SO
■Pin 19 should be connected to MCU interrupt (if using
interrupts)
■Pin 15 should be connected to CS#
■Pin 13 should be connected to SI
■Pin 32 should be connected to the active low reset output
from the MCU
■Pin 9 should be connected to SCK
J39 Routing for GPIO9-13 Not used for XR20M1280IL32
J40 Routing for GPIO8-4 Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (not used for XR20M1280IL32)
TABLE 4: JUMPER SETTINGS FOR XR20M1280IL32
JUMPERS FUNCTIONS COMMENTS

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XR20M1280 EVALUATION BOARD USER’S MANUAL REV. 1.0.0
1.2.3 XR20M1280IL40
The following jumpers apply to the XR20M1280IL40:
TABLE 5: JUMPER SETTINGS FOR XR20M1280IL40
JUMPERS FUNCTIONS COMMENTS
J12 Selects the supply voltage for UART
modem I/Os including GPIO3-GPIO0
(VCC_UART)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J13 Selects the supply voltage for UART core
logic (VCC_CORE)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J14 Selects the supply voltage for CPU bus
interface (VCC_BUS)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J15 Selects the supply voltage for GPIO15-
GPIO4 (VCC_GPIO)
Jumper in 1&2 selects 3.3V (default)
Jumper in 3&4 selects 2.5V
Jumper in 5&6 selects 1.8V
J52 Selects 5V source for regulator to 1.8V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J53 Selects 5V source for regulator to 2.5V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J54 Selects 5V source for regulator to 3.3V Jumper in 1&2 selects 5V source from J9 pins 34 &36 (default)
Jumper in 2&3 selects 5V source from +P
J36 Selects between I2C and SPI mode Jumper in selects SPI mode (default for XR20M1280L40-0B-EB)
Jumper out selects I2C mode (default for XR20M1280L40-0A-EB)
J18 Power for the SP337 RS-232/RS-485
Transceiver
Jumper not installed
Trace between 1&2
J19 Header for RS-485/422 signals RS-485/422 signals are accessible at this header
J20 SP337 Mode Control pins RS-232 Mode - No jumpers installed
RS-485 Mode - Jumpers between 1&2, 5&6
J34 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
J37 Routing of modem signals to SP337 RS-
232/RS-485 Transceiver
Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
J35 Enable/Disable Auto RS-485 mode at
power-up
(can be enabled/disabled in software after
power-up)
J35 in enables Auto RS-485 mode at power-up
J35 out disables Auto RS-485 mode at power-up

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REV. 1.0.0 XR20M1280 EVALUATION BOARD USER’S MANUAL
J44 Enable/Disable IR mode at power-up
(can be enabled/disabled in software after
power-up)
J44 in enables IR mode at power-up
J44 out disables IR mode at power-up
J50 SLEEP/PWRDN pin Header installed, no jumpers installed (default)
Refer to the datasheet for the behavior of this pin
J51 UART Reset input Jumper on 1&2 selects J2 as hardware reset
Jumper on 2&3 selects external reset from J9 pin 32 (default)
J10 I2C Address Select (A0)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
J11 I2C Address Select (A1)
■1&2 = VCC
■3&4 = SCL
■5&6 = SDA
■7&8 = GND
For I2C mode, only one jumper should be selected. See
XR20M1280 datasheet for I2C addressing.
For SPI mode, jumper should be out.
J9 Header for connection to external micro-
controller board
■Pin 23 = SDA signal for I2C
interface
■Pin 11 = SO signal for SPI
interface
■Pin 19 = IRQ# output signal from
XR20M1170
■Pin 15 = A0 signal for I2C interface
or CS# for SPI interface
■Pin 13 = A1 signal for I2C interface
or SI for SPI interface
■Pin 32 = RESET# input signal
■Pin 9 = SCK for SPI interface
(Jumper on J8 1&2)
■Pin 29 = SCL signal for I2C
interface or (Jumper on J9 2&3)
■Pin 5, 6, 7, 8, 31, 35 = GND signal
■Pin 34 & 36 = External +5V power
Ground and Power connections
■Pin 5, 6, 7, 8, 31 or 35 should be connected to GND
■Pin 34 or 36 should be connected +5V
If I2C interface is used (defaults for XR20M1280IL40-0A-EB):
■Pin 23 should be connected to SDA
■Pin 19 should be connected to MCU interrupt input (if using
interrupts)
■Pin 15 should be unconnected when using J10
■Pin 13 should be unconnected when using J11
■Pin 32 should be connected to the active low reset output
from the MCU
■Pin 29 should be connected to SCL
If SPI interface is used (defaults for XR20M1280IL40-0B-EB):
■Pin 23 should be unconnected
■Pin 11 should be connected to SO
■Pin 19 should be connected to MCU interrupt (if using
interrupts)
■Pin 15 should be connected to CS#
■Pin 13 should be connected to SI
■Pin 32 should be connected to the active low reset output
from the MCU
■Pin 9 should be connected to SCK
TABLE 5: JUMPER SETTINGS FOR XR20M1280IL40
JUMPERS FUNCTIONS COMMENTS

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NOTICE
EXAR Corporation reserves the right to make changes to the products contained in this publication in order to
improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any
circuits described herein, conveys no license under any patent or other right, and makes no representation that
the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration
purposes and may vary depending upon a user’s specific application. While the information in this publication
has been carefully checked; no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the
failure or malfunction of the product can reasonably be expected to cause failure of the life support system or
to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless
EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has
been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately
protected under the circumstances.
Copyright 2010 EXAR Corporation
Datasheet December 2010.
Send your UART technical inquiry with technical details to hotline: [e-mail].
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
XR20M1280 EVALUATION BOARD USER’S MANUAL REV. 1.0.0
2.0 DRIVERS
For the I2C/SPI UART driver, it is recommended that you contact your microcontroller vendor first for sample
code to access devices on the I2C or SPI bus. Once you can access devices on the I2C or SPI bus, you can
use the sample code from EXAR for initializing the I2C/SPI UART as a reference for devoloping your driver.
3.0 SAMPLE INITIALIZATION ROUTINE AND SUPPORT
For a sample initialization routine or if there are any questions, send an e-mail to [e-mail].
J39 Routing for GPIO9-13 Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
J40 Routing for GPIO8-4 Trace between 1&2
Trace between 3&4
Trace between 5&6
Trace between 7&8
No trace between 9&10 (jumper installed)
TABLE 5: JUMPER SETTINGS FOR XR20M1280IL40
JUMPERS FUNCTIONS COMMENTS