Texas Instruments MSP50C6xx - Manual (Page 298)

Introduction
5-2
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-k
Ω
resistor 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.