Texas Instruments MSP50C614 - Manual (Page 302)

Introduction
5-2
5.1 Introduction
The MSP50C6xx development tools gain access to the core controller via a
serial scan interface called the Scanport. The basic elements needed to do de-
velopment with the MSP50C6xx devices are listed below in Section 5.3. The
MSP50C6xx software development tool is included with the MSP scanport in-
terface (TI part #MSPSCANPORTI/F) or MSPSI.
The mask programmed MSP50C6xx devices are available in die form to sup-
port large volume production quantities. The MSP50C614/605 devices are
available in a 100-pin 14
×
20 mm quad-flat pack (QFP) and the MSP50C604
is available in a 64 pin 10
×
10 QFP for medium volume application. The
MSP50P614 is an EPROM based version of the MSP50C614, and is available
in a 120-pin windowed ceramic pin grid array package. This EPROM based
version of the device is only available in limited quantities to support software
development. Since the MSP50P614 program memory is EPROM, each per-
son doing software development should have several of these PGA packaged
devices.
The MSP50C6xx software development tool supports non-real-time
debugging by scanning the code sequence through the MSP50C6xx scanport
without programming the EPROM. However, the rate of code execution is
limited by the speed of the PC parallel port. Any MSP50C6xx device can be
used in this debugging mode.
The MSP50P614 EPROM must be programmed to debug the code in real
time. The MSP50C6xx software development tool is used to program the
EPROM, set a breakpoint, and evaluate the internal registers after the
breakpoint is reached. 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
10–15 devices to be in the eraser at any one time, so 15–20 devices may be
required to operate efficiently. The windowed PGA version of the MSP50P614
is required for this debugging mode.
It is necessary to build preproduction application boards with a zero insertion
force PGA socket that allows the device to be easily changed during software
development. Use the PGA package pin assignment shown in Figure 1–7.
These preproduction boards also have the following requirements for the
development tools to function properly. (1) a 10 pin IDC header that connects
the MSP50P614 to the MSP Scanport Interface should be provided. (2) the
VPP pin of the MSP50P614 must be pulled up to +5V with a diode, so the
development tool can apply 12V 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 1K ohm resister between