Tinyavr ® , Megaavr ® , And Xmega ® Devices - Microchip Technology Power Debugger Manual

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4.4 tinyAVR , megaAVR
AVR devices feature various programming and debugging interfaces. Check the device data sheet for supported
interfaces of that device.
• Some tinyAVR
devices do not have on-chip debug capability at all.
• Some tinyAVR devices and some megaAVR devices have the debugWIRE interface, which connects to an on-
chip debug system known as tinyOCD. All devices with debugWIRE also have the SPI interface for in-system
programming.
• Some megaAVR devices have a JTAG interface for programming and debugging, with an on-chip debug system
also known as megaOCD. All devices with JTAG also feature the SPI interface as an alternative interface for in-
system programming.
• All AVR XMEGA devices have the PDI interface for programming and debugging. Some AVR XMEGA devices
also have a JTAG interface with identical functionality.
• New tinyAVR devices have a UPDI interface, which is used for programming and debugging
Table 4-9. Programming and Debugging Interfaces Summary
UPDI
tinyAVR New
devices
megaAVR
AVR
XMEGA
AVR UC
SAM
4.4.1 JTAG Physical Interface
The JTAG interface consists of a 4-wire Test Access Port (TAP) controller that is compliant with the IEEE
standard. The IEEE standard was developed to provide an industry-standard way to efficiently test circuit board
connectivity (Boundary Scan). Microchip AVR and SAM devices have extended this functionality to include full
Programming and On-chip Debugging support.
Figure 4-9. JTAG Interface Basics
4.4.2 Connecting to a JTAG Target
The Power Debugger is equipped with two 50-mil 10-pin JTAG connectors. Both connectors are directly electrically
connected, but conform to two different pinouts; the AVR JTAG header and the ARM Cortex Debug header. The
©
2020 Microchip Technology Inc.
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, and XMEGA
®
devices have a TPI interface. TPI can be used for programming the device only, and these
TPI SPI
Some Some
devices devices
All devices Some devices
programmer /
debugger
®
Devices
debugWIRE JTAG
Some devices
Some
devices
Some
devices
All devices
Some
devices
TCK
TMS
TDI
TDO
User Guide
Power Debugger
On-chip Debugging
PDI aWire
All devices
Some
devices
All devices
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1149.1
Vcc
target
device
DS40002201A-page 64
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