Datasheet

15
ATmega16(L)
2466LS–AVR–06/05
Errata The revision letter in this section refers to the revision of the ATmega16 device.
ATmega16(L) Rev. I • IDCODE masks data from TDI input
1. IDCODE masks data from TDI input
The JTAG instruction IDCODE is not working correctly. Data to succeeding devices
are replaced by all-ones during Update-DR.
Problem Fix / Workaround
– If ATmega16 is the only device in the scan chain, the problem is not visible.
– Select the Device ID Register of the ATmega16 by issuing the IDCODE
instruction or by entering the Test-Logic-Reset state of the TAP controller to
read out the contents of its Device ID Register and possibly data from
succeeding devices of the scan chain. Issue the BYPASS instruction to the
ATmega16 while reading the Device ID Registers of preceding devices of the
boundary scan chain.
– If the Device IDs of all devices in the boundary scan chain must be captured
simultaneously, the ATmega16 must be the fist device in the chain.
ATmega16(L) Rev. H • IDCODE masks data from TDI input
1. IDCODE masks data from TDI input
The JTAG instruction IDCODE is not working correctly. Data to succeeding devices
are replaced by all-ones during Update-DR.
Problem Fix / Workaround
– If ATmega16 is the only device in the scan chain, the problem is not visible.
– Select the Device ID Register of the ATmega16 by issuing the IDCODE
instruction or by entering the Test-Logic-Reset state of the TAP controller to
read out the contents of its Device ID Register and possibly data from
succeeding devices of the scan chain. Issue the BYPASS instruction to the
ATmega16 while reading the Device ID Registers of preceding devices of the
boundary scan chain.
– If the Device IDs of all devices in the boundary scan chain must be captured
simultaneously, the ATmega16 must be the fist device in the chain.
ATmega16(L) Rev. G • IDCODE masks data from TDI input
1. IDCODE masks data from TDI input
The JTAG instruction IDCODE is not working correctly. Data to succeeding devices
are replaced by all-ones during Update-DR.
Problem Fix / Workaround
– If ATmega16 is the only device in the scan chain, the problem is not visible.
– Select the Device ID Register of the ATmega16 by issuing the IDCODE
instruction or by entering the Test-Logic-Reset state of the TAP controller to
read out the contents of its Device ID Register and possibly data from
succeeding devices of the scan chain. Issue the BYPASS instruction to the
ATmega16 while reading the Device ID Registers of preceding devices of the
boundary scan chain.
– If the Device IDs of all devices in the boundary scan chain must be captured
simultaneously, the ATmega16 must be the fist device in the chain.