AT90USB1286-16MU ATMEL [ATMEL Corporation], AT90USB1286-16MU Datasheet - Page 345
![no-image](/images/no-image-200.jpg)
AT90USB1286-16MU
Manufacturer Part Number
AT90USB1286-16MU
Description
Microcontroller with 64/128K Bytes of ISP Flash and USB Controller
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT90USB1286-16MU.pdf
(434 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
- Current page: 345 of 434
- Download datasheet (4Mb)
27.5.2
27.6
27.6.1
7593A–AVR–02/06
Boundary-scan Chain
MCU Status Register – MCUSR
Scanning the Digital Port Pins
The MCU Status Register provides information on which reset source caused an MCU reset.
• Bit 4 – JTRF: JTAG Reset Flag
This bit is set if a reset is being caused by a logic one in the JTAG Reset Register selected by
the JTAG instruction AVR_RESET. This bit is reset by a Power-on Reset, or by writing a logic
zero to the flag.
The Boundary-scan chain has the capability of driving and observing the logic levels on the digi-
tal I/O pins, as well as the boundary between digital and analog logic for analog circuitry having
off-chip connection.
Figure 27-3
disabled during Boundary-scan when the JTAG IC contains EXTEST or SAMPLE_PRELOAD.
The cell consists of a bi-directional pin cell that combines the three signals Output Control -
OCxn, Output Data - ODxn, and Input Data - IDxn, into only a two-stage Shift Register. The port
and pin indexes are not used in the following description
The Boundary-scan logic is not included in the figures in the datasheet.
simple digital port pin as described in the section
details from
When no alternate port function is present, the Input Data - ID - corresponds to the PINxn Regis-
ter value (but ID has no synchronizer), Output Data corresponds to the PORT Register, Output
Control corresponds to the Data Direction - DD Register, and the Pull-up Enable - PUExn - cor-
responds to logic expression PUD · DDxn · PORTxn.
Digital alternate port functions are connected outside the dotted box in
scan chain read the actual pin value. For analog function, there is a direct connection from the
external pin to the analog circuit. There is no scan chain on the interface between the digital and
the analog circuitry, but some digital control signal to analog circuitry are turned off to avoid driv-
ing contention on the pads.
When JTAG IR contains EXTEST or SAMPLE_PRELOAD the clock is not sent out on the port
pins even if the CKOUT fuse is programmed. Even though the clock is output when the JTAG IR
contains SAMPLE_PRELOAD, the clock is not sampled by the boundary scan.
Bit
Read/Write
Initial Value
Figure 27-3
shows the Boundary-scan Cell for a bi-directional port pin. The pull-up function is
7
–
R
0
R
6
–
0
replaces the dashed box in
R
5
–
0
R/W
4
JTRF
See Bit Description
3
WDRF
R/W
“I/O-Ports” on page
Figure
2
BORF
R/W
27-4.
1
EXTRF
R/W
AT90USB64/128
Figure 27-4
73. The Boundary-scan
0
PORF
R/W
Figure 27-4
MCUSR
to make the
shows a
345
Related parts for AT90USB1286-16MU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![AT90USBKEY](/photos/15/94/159427/at90usbkey_tmb.jpg)
Part Number:
Description:
MCU, MPU & DSP Development Tools Demo board f/AVR MCU & AT90USB
Manufacturer:
Atmel
Datasheet:
![AT88SC0204CA-SH](/images/no-image3.png)
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![AT88SC0808CA-SH](/images/no-image3.png)
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![AT88SC1616C-SH](/images/no-image3.png)
Part Number:
Description:
Atmel CryptoMemory, 16Kbit
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![AT25DF161-SH](/images/no-image3.png)
Part Number:
Description:
8-bit Atmel Microcontrollers
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![ATMEGA1281V](/images/no-image3.png)
Part Number:
Description:
8-bit Atmel Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![ATMEGA164A_11](/images/no-image3.png)
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64/128K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
![U641B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
![U4082B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
![U4255BM-M](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B-P](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
![TDA4470](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet: