NXP Semiconductors PCAL6416AEV-ARD User manual

UM11704
PCAL6416AEV-ARD evaluation board
Rev. 1.0 — 1 December 2021 User manual
Document information
Information Content
Keywords PCAL6416A, I2C-bus, 16-bit I/O bus, Arduino port, EVK
Abstract The PCAL6416AEV-ARD evaluation board is a daughter card equipped with
Arduino port, designed for easy test and design of PCAL6416A IC, 16-bit
port expander, controlled through FM I2C 2-wire bus, with RESET. The board
is fully compliant with IMXRT1050 EVK, LPCXpresso55S69 (LPC55S69-
ECK) and i.MX 8M Mini LPDDR4 EVK (8MMINILPD4-EVK, 8MMINID4-EVK),
including GUI software control. The board can be attached to any device
equipped with Arduino port.

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
Rev Date Description
v.1.0 20211201 Initial version
Revision history
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
2 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
IMPORTANT NOTICE
For engineering development or evaluation purposes only
NXP provides the product under the following conditions:
This evaluation kit is for use of ENGINEERING DEVELOPMENT OR
EVALUATION PURPOSES ONLY. It is provided as a sample IC pre-
soldered to a printed-circuit board to make it easier to access inputs,
outputs and supply terminals. This evaluation board may be used with any
development system or other source of I/O signals by connecting it to the
host MCU computer board via off-the-shelf cables. This evaluation board
is not a Reference Design and is not intended to represent a final design
recommendation for any particular application. Final device in an application
heavily depends on proper printed-circuit board layout and heat sinking
design as well as attention to supply filtering, transient suppression, and I/O
signal quality.
The product provided may not be complete in terms of required design,
marketing, and or manufacturing related protective considerations, including
product safety measures typically found in the end device incorporating the
product. Due to the open construction of the product, it is the responsibility of
the user to take all appropriate precautions for electric discharge. In order to
minimize risks associated with the customers’ applications, adequate design
and operating safeguards must be provided by the customer to minimize
inherent or procedural hazards. For any safety concerns, contact NXP sales
and technical support services.
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
3 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
1 Introduction
This document describes the PCAL6416AEV-ARD evaluation board. The evaluation
board is built around the PCAL6416A, low-voltage translating, 16-bit I2C-bus/SMBus I/
O expander with interrupt output, reset, and configuration registers, produced by NXP
Semiconductors. The evaluation board serves as a daughter card that can be connected
through an Arduino port to various Arduino compatible (including original Arduino Uno
R3) EVK / mother boards with the purpose of testing and measuring the characteristics of
the PCAL6416A Device Under Test (DUT).
The PCAL6416AEV-ARD daughter card communicates through the Arduino port with
the host device via the Fast-mode I2C-bus. Alongside the I2C bus, three additional digital
lines allow the mother board to control the DUT through the same Arduino port.
Power is also delivered from the mother board (EVK) through the Arduino port.
The board contains eight on-board LEDs and eight switches, connected to the I/O pins of
the DUT. The same I/O bus is shared with a connector for external access to the I/O pins.
Additionally, a Graphical User Interface (Windows platform) is provided to facilitate the
evaluation of the daughter board. The GUI is used with the following NXP evaluation
boards: IMXRT1050 EVK Board, LPCXpresso55S69 Development Board and i.MX 8M
Mini LPDDR4 EVK Board.
2 Finding kit resources and information on the NXP web site
NXP Semiconductors provides online resources for evaluation board and its supported
device(s) on http://www.nxp.com.
The information page for PCAL6416AEV-ARD evaluation board is at http://http://
www.nxp.com/PCAL6416AEV-ARD. The information page provides overview information,
documentation, software and tools, parametrics, ordering information and a Getting
Started tab. The Getting Started tab provides quick-reference information applicable
to using the PCAL6416AEV-ARD evaluation board, including the downloadable assets
referenced in this document.
2.1 Collaborate in the NXP community
The NXP community is for sharing ideas and tips, ask and answer technical questions,
and receive input on just about any embedded design topic.
The NXP community is at http://community.nxp.com.
3 Getting ready
Working with the PCAL6416AEV-ARD requires the kit contents, additional hardware, and
a Windows PC workstation with installed software.
3.1 Kit contents
•Assembled and tested evaluation board in an antistatic bag
•Quick Start Guide
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
4 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
3.2 Assumptions
Familiarity with the I2C bus is helpful but not required.
3.3 Static handling requirements
CAUTION
This device is sensitive to ElectroStatic Discharge (ESD). Therefore care
should be taken during transport and handling. You must use a ground strap
or touch the PC case or other grounded source before unpacking or handling
the hardware.
3.4 Minimum system requirements
This evaluation board requires a Windows PC workstation. Meeting these minimum
specifications should produce great results when working with this evaluation board.
•Computer with Windows 10
•One USB port (either 3.0 or 2.0 or 1.1 compatible)
•One of three EVK boards (MIMXRT1050-EVK, LPC55S69-EVK, 8MMINILPD4-EVK)
along with the associated firmware / GUI software
•USB cable for power and data connection between PC and EVK board (if not included
in the EVK package)
4 Getting to know the hardware
4.1 PCAL6416AEV-ARD features
•I/O connector for external access to IC input-output pins
•8 user switches connected to I/O pins of the IC
•8 user LEDs connected to I/O pins of the IC
•Equipped with Arduino Uno R3 port for direct connection with Arduino devices
•Fully compliant with IMXRT1050 EVK board, including GUI (Windows 10)
•Fully compliant with LPCXpresso55S69 dev. board, including GUI (Windows 10)
•Compliant with i.MX Mini LPDDR4 EVK board, including GUI (Windows 10)
Note: For i.MX Mini LPDDR4 EVK Board is necessary to use IMX8MMINI-IARD
interposer board between the EVK and PCAL6416AEV-ARD daughter board (see
IMX8MMINI-IARD User Manual).
4.2 Kit featured components
Figure 1 identifies the main components on the board. The main elements are called out
in the picture. The Arduino port connectors (J1, J2, J3, J4) are located on the bottom side
of the board.
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
5 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
Figure 1. The PCAL6416AEV-ARD board picture, top view (up) and bottom view (down)
4.3 Block diagram
Figure 2 shows a block diagram of the PCAL6416AEV-ARD daughter board. Alongside
the DUT (U2), the block diagram includes Arduino interface (J1, J2, J3, and J4
connectors), the I/O external connector (J5), the on-board LEDs (D4 to D11), and
switches (SW1 to SW8).
The IC is connected to Arduino interface through two buses: a 3-bit control bus (J3) and
the I2C-bus (J2). The I/O pins are connected to 16-bit I/O port (J5) for direct access from
external. On the I/O digital lines are connected eight LEDs (the P0 port of PCAL6416A
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
6 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
IC) and eight push button switches (the P1 port). U1 is a 3.3V power rail regulator. The
3.3V power rail provides the power supply, both for PCAL6416A and LEDs.
Figure 2. PCAL6416AEV-ARD block diagram
4.4 Schematic diagram
The schematic diagram of PCAL6416AEV-ARD is available at URL: http://www.nxp.com/
PCAL6416AEV-ARD.
4.5 Arduino port
J1, J2, J3, and J4 are the mated pin headers of Arduino Uno R3 connectors, having the
same electrical function and placed on the board, so that the daughter board can be
directly inserted in the Arduino port. The daughter card is using only five signal lines.
Table 1 represents the pin chart of connectors, and the used lines in the circuit (see also
the SPF-46663.pdf schematic file):
Ref Des # Arduino label PCAL6416AEV-ARD function
1 NC Not used
2 IOREF Not used
3 RESET Not used
4 3.3V Not used
5 5V Power supply
6 GND Power supply return
7 GND Power supply return
J1 (Power)
8 Vin Not used
1 A0 Not used
2 A1 Not used
3 A2 Not used
4 A3 Not used
J2 (analog, digital, I2C)
5 A4 / SDA I2C – SDA
Table 1. Pin chart of Arduino connectors
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
7 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
Ref Des # Arduino label PCAL6416AEV-ARD function
6 A5 / SCL I2C – SCL
1 D0 / RX Not used
2 D1 / TX Not used
3 D2 Not used
4 D3 / PWM Not used
5 D4 Not used
6 D5 / PWM Not used
7 D6 / PWM Not used
J4 (digital, UART, PWM)
8 D7 Not used
1 D8 RESET (control bus)
2 D9 / PWM ADDR (control bus)
3 D10 / SS / PWM INT (control bus)
4 D11 / MOSI / PWM Not used
5 D12 / MISO Not used
6 D13 / SCK Not used
7 GND Power supply return
8 AREF Not used
9 A4 / SDA Not used
J3 (mixed)
10 A5 / SCL Not used
Table 1. Pin chart of Arduino connectors...continued
The circuit is supplied with 5V from Arduino port through J1 and J3. Pin no. 5 of J1 is 5V
power supply, while pin no. 6, 7 of J1, and pin no. 7 of J3 represents the power supply
return (ground).
4.6 I2C bus
The PCAL6416A communicates with the host through an I2C bus (pin A5 – SCL, pin A4
– SDA). The communication provides internal configuration of the I/O expander, reads
the logic levels of the I/O pins configured as inputs, and sets the logic level on the I/O
pins configured as outputs. The internal configuration of the DUT includes direction of
the digital I/O lines (input or output), polarity inversion, pull-up / pull-down resistor enable,
output strength, output configuration (push-pull or open-drain), input latch configuration,
and interrupt register. The transaction speed of the I2C bus is compliant with Standard-
mode (100kHz), and Fast-mode (400kHz). For more details about I2C description and
bus transactions, see PCAL6416A datasheet (NXP Semiconductors). The pull-up
resistors of the I2C bus are R2 and R3 (see SPF-46663.pdf schematic file).
4.7 Control bus
The control bus manages the RESET, ADDR, and INT pins of the PCAL6416A IC. The
RESET pin is digital input and is controlled by the system host. Its role is to reset the I/
O expander when a time-out or other improper operation occurs. Asserting a low level of
this line forces a reset operation of the internal control section of the IC (puts the internal
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
8 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
registers in their default state and force a re-initialization of the I2C state machine, in
the same manner as power-on sequence). The RESET pin is controlled by the EVK
motherboard through J3-1 (Arduino port).
The ADDR pin is digital input and represents a programmable hardware address
package which can be asserted low or high, to assign two different slave addresses. The
input is controlled by the EVK through J3-2 (Arduino port).
The INT pin is an open-drain interrupt output, activated when any input state differs from
its corresponding input port register state, indicating to the host system that an input state
has changed. The line is monitored by the EVK through J3-3 Arduino port and locally
by the LED (D3) located on the daughter board. The LED D3 can be deactivated by
removing JP1 jumper. When D3 is inactive (JP1 removed) the open-drain is polarized
through R5. R5 also has the role to compensate the voltage drop of D3 assuring 3.3V
high level in high state of the interrupt line (see SPF-46663.pdf schematic file).
4.8 I/O bus
The port P0 of the DUT is configured as output. The lines drive the on-board LEDs D4
to D11. The P1 port is configured as input. The on-board switches SW1 to SW8 are
connected on the inputs, so that the user can change the logic state from the switches
located on the daughter board. Both ports P0 and P1 are connected to connector J5.
Table 2 shows the configuration of the I/O bus of the PCAL6416AEV-ARD daughter
board.
U2 pin name (number) Wire label On-board LEDs On-board switches I/O ext. conn. (J5)
P0_0 (A1) IO_0 D4 - 3
P0_1 (C3) IO_1 D5 - 4
P0_2 (B1) IO_2 D6 - 5
P0_3 (C1) IO_3 D7 - 6
P0_4 (C2) IO_4 D8 - 7
P0_5 (D1) IO_5 D9 - 8
P0_6 (E1) IO_6 D10 - 9
P0_7 (D2) IO_7 D11 - 10
P1_0 (E3) IO_8 - SW1 11
P1_1 (E4) IO_9 - SW2 12
P1_2 (D3) IO_10 - SW3 13
P1_3 (E5) IO_11 - SW4 14
P1_4 (D4) IO_12 - SW5 15
P1_5 (D5) IO_13 - SW6 16
P1_6 (C5) IO_14 - SW7 17
P1_7 (C4) IO_15 - SW8 18
Table 2. J5 pin chart
The on- board LEDs can be disabled by placing JP2 jumper in 2-3 position (OPTION
1, see SPF-46663.pdf file). This feature is useful when the user uses the board with
external device connected to J5 I/O port. The switches are connected to the bus through
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
9 / 25

NXP Semiconductors UM11704
PCAL6416AEV-ARD evaluation board
620Ω series resistors (R15 – R22), to avoid bus conflict (short-circuit if the line is set
accidentally as output and the switch is pressed).
4.9 Jumpers and test points
The board contains two jumpers and several test points. Table 3 and Figure 3 details
the jumper locations and their default configurations. Table 4 describes the test points
located on the PCAL6416AEV-ARD board.
Ref Des Label Default Description
OFF: Disable the interrupt monitor LED (D3)
JP1 INT MONITOR ON / OFF OFF ON: Enable the interrupt monitor LED (D3)
1-2: Enable the user LEDs (D4 – D11)
JP2 USER LED – ON / OFF 1-2 2-3: Disable the user LEDs (D4 – D11)
Table 3. PCAL6416AEV-ARD jumpers
Figure 3. PCAL6416AEV-ARD jumper locations
Ref Des Test point / jumper label Description
TP1 5V The 5V power supply
TP2 3.3V The 3.3V power rail
TP3 GND Ground
Table 4. PCAL6416AEV-ARD test points
UM11704 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1.0 — 1 December 2021
10 / 25