Texas Instruments MSP50C6xx manual Introduction

Introduction

5.1 Introduction

The MSP50C6xx code development tool is a system made up of a personal computer (PC), the EMUC6xx software, an MSP scanport interface, and a MSP50P614 connected to the application circuits.

EMUC6xx is the software that executes on the PC and provides a user interface to the compiler, assembler, linker, debugger, and MSP50P614 programmer. This software gains access to the MSP50P614 and MSP50C6xx devices through a serial interface, called scanport. The MSP scanport interface (TI part number MSPSCANPORTI/F) is used to connect the scanport to an enhanced parallel port on the PC. The MSP50P614 is an EPROM based device used to emulate the MSP50C6xx devices. These EPROM based devices are packaged in a kit of 15 pieces (TI part number SDK50P614), and are only available in limited quantities to support code development.

The MSP50P614’s EPROM must be programmed to debug the code in real-time. The MSP50C6xx code development tool is used to program the EPROM, set a breakpoint, and evaluate the internal registers after the breakpoint is reached. This mode is called Run Internal. The Trace mode also requires the code to be programmed into the EPROM. If a change is made to the code, the code will need to be updated and programmed into another device while erasing previous devices. This cycle of programming, debugging, and erasing typically requires several devices to be in the eraser at any time, so 10–15 devices may be required to operate efficiently.

The MSP50C6xx code development tool also supports non-real-time debugging by scanning the code sequence through the scanport without programming the EPROM. However, the rate of code execution is limited by the speed of the PC parallel port. These modes are called Run and Fast Run.

Any preproduction applications boards being used for code development must have a 13x13, 121 pin, zero insertion force (ZIF), PGA socket that allows the MSP50P614 to be easily changed. Use the PGA package pin assignments shown in Figure 7–4. These preproduction boards also have the following requirements for the development tool to function properly. (1) A 10 pin keyed IDC connector, as shown in Figure 5–1, that connects the MSP50P614 to the MSP scanport interface should be provided. (2) The VPP pin of the MSP50P614 must be pulled up with a diode connected to VDD, so the development tool can apply 12 V to this pin. (3) The development tool must be allowed to toggle the RESET pin without being loaded by any low impedance reset circuit. This can be accomplished by inserting a 1-kΩresistor between the reset circuit and the RESET pin, and connecting the MSP scanport interface reset signal directly to the RESET pin. See the reset circuit shown in Figure 1–3.

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