[ UP ]

Overview

This interface has a better data throughput than the serial one. Additionally, it does not have to be powered from the target system because it takes power from the PC host and it supports low voltage target devices with any internal operating frequency.
The schematic is shown below:

Board controls

-Led indicators

Two LED's are provided as feedback. The Red led indicates pod’s firmware writing operations to the target’s on-chip flash or eeprom. The Green indicator lights up when USB commands are coming from the host. During downloads to memory, you may see a definite flashing of the green led. During a large memory dump, the green led may turn on and stay in that state for a while.

Pod connections

-USB Host connection

This pod connects to the host computer through an USB connection which complies with the USB 1.1 specification. Data throughput up to  37 Kbytes/sec.

-Target Connection

Connection to the Target system is made through a modified version of the standard BDM cable. The standard BDM cable is made to connect to a six pin connector as shown below:

Our modified version use a 2x5 header in order to add 2 additional signals used to control the target processor operating mode (just when it´s used with HC(S)12 microcontrollers) after an invocation of the ActiveX’s Reset method. These signals are MODA and MODB. The target connection is shown below:

As you can see, the first 6 pins share the same pin distribution as the standard connector, thereof you can use a standard 2x3 connector with this extended one.

The PCB Layout

The dimensions of the board are approx. 2.8" by 1.8". Here you can see the components layout together with the the bottom side of the PCB (just a single side board).

Download Board & Schematic

The whole project (except the pod interface’s firmware) is freely available for use. The board and schematic files of the interface together with the ActiveX control, Windows device driver and software samples which include source code can be downloaded from the project’s web site at no cost. The PIC16C745 burned with the firmware is available for only $47 US dollars. Ask for PCBs or assembled boards and firmware. Contact me for more information or place your order here.