Question:
How do smart phones and tablets work with the CY4613 kit in the Accessory Charger Adaptor Dock (ACA-Dock) mode?
Answer:
ACA-Dock enables charging and simultaneous data transfer for a mobile phone or a tablet acting as an OTG Host with support for Battery Charging Specification Version 1.2 (BC v1.2). The CY4613 kit helps you evaluate the CYUSB3328 – the industry’s only USB 3.0 Hub controller with the ACA-Dock feature. (CYUSB3328 is part of the Cypress’s EZ-USB® HX3™ product family). When a USB OTG-capable phone or tablet is connected to the CY4613 board’s upstream port, it is charged by the upstream port using HX3’s ACA-Dock feature. At the same time, the connected phone or tablet enumerates the CY4613 hub, and devices connected to the downstream ports of CY4613 work as expected.
1. Supporting BC v1.2-Compliant OTG Host Phones
The CY4613 board is designed to support BC v1.2 compliant OTG Host phones connected to the upstream (US) port. Figure 1 shows the HX3 hub system in the ACA-Dock mode as implemented in the CY4613 board.
Figure 1. HX3 Controller (CYUSB3328) in ACA-Dock Mode in CY4613
The CY4613 supports the RID_A (CY4613 schematics: R25) of 124 kΩ (standard RID_A value as per the BC v1.2 specification) by default. Refer Step 9 of the CY4613 Quick Start Guide to configure the CY4613 for ACA-Dock functionality.
When a BC v1.2–compliant OTG-capable phone, such as Sony Xperia (Neo V, P, or S), is connected to the CY4613 board’s US port, the phone is charged, and simultaneously enumerates the hub and works like a normal host controller.
2. Supporting USB OTG Capable Phone With Proprietary RID_A Values
The CY4613 board has been tested with popular tablets and phones available in the market with proprietary RID_A values. By changing the RID_A resistor (CY4613 schematics: R25) value on the CY4613 board, you can connect different phones and tablets to the CY4613 board in the ACA-Dock mode.
Table 1 provides the details on the tested phone/tablet models and the corresponding RID_A values. Figure 2 shows the HX3 hub system in the ACA-Dock mode, with modifications required to support a proprietary RID_A.
Table 1. List of Phones and Tablets Tested Using the CY4613 Board
| Manufacturer | Model and Description | RID_A Value |
| Sony | Xperia Neo V, P, and S | 122 kΩ -126 kΩ (default value as per BC v1.2 spec). Supported in CY4613 |
| Samsung | Galaxy Note Pro Tablet 12.2 | 80 kΩ - 85 kΩ |
| Samsung | Galaxy Note 2 | 71 kΩ - 74 kΩ Supported in Rev041 CY4613 |
| Samsung | Galaxy Note 3 | 71 kΩ - 74 kΩ Supported in Rev041 CY4613 |
| Samsung | Galaxy S4 phone | 71 kΩ - 74 kΩ Supported in Rev041 CY4613 |
| Samsung | Galaxy S3 phone | 71 kΩ - 74 kΩ Supported in Rev041 CY4613 |
1: Refer Appendix
Figure 2. Recommended ACA-Dock System Implementation using HX3 Controller (CYUSB3328)
Some mobile phones or tablets (for example, Samsung Galaxy Note Pro Tablet 12.2) require the RID_A termination resistor to be floating when VBUS is powered off as shown in Figure 2. For this implementation the transistor T1 (Part Number: BSN20-70 or equivalent) is required. Transistor T1 is not implemented on the CY4613 board and RID_A is directly connected to ground (as in Figure 1). However it is highly advised to use the transistor T1 in ACA-Dock system designs.
3. HX3 and PSoC4 Based Generic ACA-Dock Solution Supporting Various RID_A Values
A mobile phone or tablet connected to the Upstream (US) port of HX3 monitors the resistor (RID_A) value connected to the ID pin (Refer Figure 3). If the RID_A value matches resistance value expected by the phone or tablet (OTG Host), the host allows enumeration of HX3 and devices connected to the Downstream (DS) port of HX3.
In order to enable ACA-Dock functionality for various phones and tablets which support either standard or proprietary RID_A resistor value, a solution which varies the value of resistor RID_A is required. This solution can be implemented by interfacing the PSoC4 Pioneer board with the HX3 CY4613 board. Figure 3 shows the block diagram of the solution implementation.
Figure 3. HX3 and PSoC4 Based Generic ACA-Dock Solution Block Diagram
Interface between the HX3 CY4613 board and PSOC4 Pioneer board are as follows:
1) SUSPEND pin: SUSPEND pin is held high when HX3’s US port is not connected to any host controller. SUSPEND is pulled to low only when HX3 is successfully enumerated by the host connected to the US port. PSoC4 monitors the SUSPEND pin to identify successful enumeration. Enumeration process takes up to one second.
2) ID pin of US USB Connector: The ID pin of the US port is connected to the output of the iDAC in the PSoC 4. PSoC4 will vary the current driven on the ID pin to emulate varying RID_A values.
3) Power and Ground: The Pioneer board is powered by the CY4613 board. This implementation ensures that resistor RID_A is floating when there is no power supply to the CY4613 and the Pioneer boards.
The algorithm implemented on the PSoC 4 is as follows:
Step 1:
PSoC4 detects the Connect or Disconnect event on the HX3’s US port by monitoring the ID pin. If a Connect event is detected, Step 2 is initiated. If a Disconnect event is detected, the PSoC4 will automatically reset.
Step 2:
PSoC4 assumes three possible RID values as default (72 KΩ, 80 KΩ and 124 KΩ). PSoC4 sets the iDAC value to emulate these default RID_A values and monitors SUSPEND. If enumeration (SUSPEND = 0) is successful for any one of these values, the PSoC4 device locks the iDAC current. If enumeration is not successful (SUSPEND = 1), Step 3 is initiated.
Step 3:
The PSoC4 starts ramping the current driven on the iDAC in steps of 2.4 uA. For each step the SUSPEND pin is monitored for 1 sec. If the enumeration is not successful, the current is increased by one step of 2.4 uA.
This process is repeated until the HX3 is successfully enumerated by the phone or tablet (OTG Host). If connected phone or tablet is not ACA-Dock capable, PSoC4 will stop driving iDAC and wait for disconnection event to happen (phone or tablet disconnected from US port).
4. Step-by-Step instruction to implement Generic ACA-Dock Solution using the HX3 DVK and PSoC4 Pioneer Kit
Prepare CY4613 board:
a) Take a CY4613 board and configure it to enable the ACA Dock feature. Refer Step 9 of the CY4613 Quick Start Guide to configure the CY4613 for ACA-Dock functionality.
b) Solder a wire to the Suspend LED (SUSP) on the CY4613 board as shown in Figure 4.
Figure 4. CY4613 Board with a wire soldered to the Suspend LED
Prepare Pioneer Board
c) Download PSoC Creator from http://www.cypress.com/go/creator. For features, system requirements, and installation notes, refer to http://www.cypress.com/PSoCcreator.
d) Download the PSoC4 Creator project (.zip file) from http://www.cypress.com/go/ACA-Dock-Feature. Unzip the file and save in local directory. Read the “Release Notes.pdf” file in the unzipped files for known limitations. Double click the “*.cywrk” file from the unzipped files. This will open the PSoC Creator software.
e) Connect the PSoC4 Pioneer board to the PC using the USB cable provided with the Pioneer kit.
f) “Program” the Pioneer kit by selecting Debug > Program as shown in Figure 5. On successful completion of programming, the output window should read “PSoC 4 CY8C4245AX*-483' was successfully programmed” as shown in Figure 5.
Figure 5. PSOC4 Programming using the PSoC Creator Tool
Figure 6. PSoC4 Pioneer Board Back and Front View (with 27KΩ connected)
Interconnecting the CY4613 Board and the PSOC4 Pioneer Board
h) On the CY4613 board, remove the Jumper J27 and connect the pin 1 of the J27 to pin P1_0 of the Pioneer board. (Blue wire in Figure 7).
i) Connect the wire previously soldered onto the CY4613 (from SUSP LED) to P0_4 of the Pioneer bard (Yellow wire in Figure 7)
j) Remove the Jumper J9 from the Pioneer board and connect J9’s center pin to the pin 1 of J23 on the 4613 DVK. (Red wire in Figure 7) This connects VDD from CY4613 to Pioneer board.
k) Connect pin 4 of jumper J23 on CY4613 to any one of the ground pins (GND) of Pioneer board (Black wire in Figure 7)
Figure 7. PSoC4 Pioneer kit and CY4613 DVK Interconnected with 4 wires
Appendix:
Question: How to identify Rev04 CY4613 board?
Answer: The revision number is printed on the back of the CY4613 board as shown in Figure 8
Figure 8: Back-Side of CY4613 with Marking of Revision Number
Question: How is the Rev04 CY4613 different from the previous CY4613 boards?
Answer:
Rev04 CY4613 board
Supports two RID_A values: 124 kΩ and 73.2 kΩ
RID_A selection jumper (J27) is a 3 pin jumper
The RID_A can be set to 124 kΩ by setting jumper J27 to connect Pin 1 and Pin 2.
The RID_A can be set to 73.2 kΩ by setting jumper J27 to connect Pin 2 and Pin 3.
Previous CY4613 board
Supports RID_A value of 124 kΩ
RID_A selection jumper (J27) is a 2 pin jumper
The RIA_A can be set to 124 kΩ by setting jumper J27 to connect Pin 1 and Pin 2