Author: HPPC Version: **
This article describes the procedure to exercise the JTAG master capability of a USB-Serial device (CY7C65215-32LTXI) on the CYUSBS236 USB-Serial Development Kit.
The USB-Serial device can act as a JTAG master at a rate of 400 kHz. The serial communication block 1 (SCB1) can be configured as a JTAG interface (vendor class) using the USB-Serial Configuration Utility.
Pin mapping on the USB-Serial device for the JTAG signals is as follows:
Table 1: JTAG Signals on the USB-Serial Device
USB Serial Pins
SCB1_1 (Pin 6)
SCB1_0 (Pin 5)
SCB1_2 (Pin 7)
SCB1_3 (Pin 8)
SCB1_4 (Pin 9)
Figure 1: CYUSBS236 USB-Serial Development Kit
The JTAG functionality of USB-Serial (CY7C65215) can be demonstrated using the CYUSBS236 USB-Serial Development Kit and EZ-USB FX3™ (CYUSB3014), where USB-Serial acts as JTAG master and EZ-USB FX3 acts as JTAG slave. In this setup, USB-Serial is used as a USB-JTAG interface and can debug the EZ-USB FX3 firmware. The hardware connections need to be wired as follows:
Table 2: CYUSBS236 DVK to FX3 Connections
1. Install the EZ-USB FX3 Software Development Kit (SDK).
2. Connect the EZ-USB FX3 and USB-Serial device to the PC, and bind both to the corresponding drivers. The driver binding procedure for USB-Serial is available at: <Install directory>\CYUSBS236 DVK\1.0\documentation\Cypress USB-Serial Driver Installation Guide.pdf.
3. Configure the USB-Serial device as a JTAG device using the USB-Serial Configuration Utility.
4. The instructions for debugging the EZ-USB FX3 firmware are available in the EZ-USB FX3 SDK installation directory:
<Install directory>\EZ-USB FX3 SDK\1.3\doc\firmware\EzUsbSuite_UG.pdf.
5. The EZ-USB FX3 SDK uses the Eclipse™ IDE to build the firmware and launch the standard GNU debugger GDB used by the OpenOCD server for debugging purpose.
- On Windows 32-bit platforms, the default <Install directory> is C:\Program files\Cypress; on Windows 64-bit platforms, it is C:\Program files(X86)\Cypress.
- A custom firmware is required to implement UART communication on SCB0 while SCB1 is being used for JTAG communication.