AN987 Datasheet, PDF (2/10 Pages) STMicroelectronics – ST7 SERIAL TEST CONTROLLER PROGRAMMING

ST7 SERIAL TEST CONTROLLER PROGRAMMING
2 SERIAL TEST CONTROLLER PROGRAMMING
2.1 ADVANTAGES
The advantages of STCP are numerous:
s Time to market
To reduce manufacturing cycle times, a user board can be designed to be generic,
supporting several functions. These functions can be enabled or disabled by software
according to customer requirements. In this case, STCP allows application boards to be
manufactured in one shot and programmed with different functions according to customer
needs and orders.
s Cost reduction
Software updates may be necessary in some cases because of a bug correction or a newly
implemented feature. The STCP is a flexible and painless way of performing such
modifications and at a lower cost. There is no need to add any sockets to the board or to
unsolder and change components in order to upgrade the application.
s Security
Because STCP offers an easy way to customise the user’s program, or part of it, it can be
used to insert different key codes for each board. This could be used, for example, in a door
lock system.
s Flexibility
For example, STCP can be used to allow calibration procedures to be performed directly in
the field.
2.2 USER BOARD SPECIFICATION
The user has to design his layout in order to support two modes: programming mode and user
mode.
Figure 1. shows the user board divided into two blocks:
s Block 1:
Includes all the components that play a role during programming mode:
– Connector J1, which links the user board to the programming tool.
– The ST72 MCU, which is the device to be programmed.
– Jumpers W1 to Wn, whose purpose is to isolate the pins used for programming the ST72
from the other components in Block 2. In some application configurations, isolation resis-
tors (47 kΩ) can be used instead of jumpers.
s Block 2:
This block consists of all the other components soldered on the user board.
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