MXT1664T3-ABESSQTP datasheet(68/98 Pages) MICROCHIP

68 / 98 page

MXT1664T3 2.0

DS40002054A-page 68

 2018 Microchip Technology Inc.

13.0

DEBUGGING AND TUNING

13.1

SPI Debug Interface

13.2

USB Debug Interface

If the USB interface is in use on the device, this can be used as the hardware debug interface instead of the SPI Debug

Interface.

The USB hardware debugging interface is enabled by the Command Processor T6 object and by default will be off.

13.3

Object-based Protocol

The device provides a mechanism for obtaining debug data for development and testing purposes by reading data from

the Diagnostic Debug T37 object.

13.4

Self Test

There is a Self Test T25 object that runs self-test routines in the device to find hardware faults on the sense lines and

the electrodes. This object also performs an initial pin fault test on power-up to ensure that there is no pin short (X-to-

Y, or sense pin to power or GND) before the high-voltage supply is enabled inside the chip. A high-voltage short on the

sense lines could damage the device.

The SPI Debug Interface is used for tuning and debugging when running the system and allows the development

engineer to use Microchip maXTouch Studio to read the real-time raw data. This uses the low-level debug port.

The SPI Debug Interface consists of the DBG_SS, DBG_CLK, and DBG_DATA lines. It is recommended that these pins

are routed to test points on all designs such that they can be connected to external hardware during system

development. These lines should not be connected to power or GND. See Section 2.5.9 “SPI Debug Interface” for more

details.

The SPI Debug Interface is enabled by the Command Processor T6 object and by default will be off.

NOTE

The touch controller will take care of the pin configuration. When the DBG_SS, DBG_CLK, and

DBG_DATA lines are in use for debugging, any alternative function for the pins cannot be used.

NOTE

The Diagnostic Debug T37 object is of most use for simple tuning purposes. When debugging a design, it

is preferable to use the SPI Debug Interface, as this will have a much higher bandwidth and can provide

real-time data.

MXT1664T3-ABESSQTP датащи(PDF) 68 Page - Microchip Technology