2.4.1 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.
Work Around
- The problem is not visible if ATmega32A is the only device in the scan chain
- Select the Device ID Register of the ATmega32A 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 ATmega32A 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 are captured simultaneously, the ATmega32A must be the first device in the chain
Affected Silicon Revisions
| ATmega32A | ||
|---|---|---|
| Rev. G | Rev. I | Rev. K |
| X | X | X |